diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
index dae109fd6..c73390a81 100644
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -44,6 +44,10 @@
 - Type-annotate all public function signatures.
 - Docstrings on all public classes and methods (numpy style). These must
   include sections Parameters, Returns and Raises, where applicable.
+- Docstring summary must be a single line no longer than 72 characters
+  (the `max-doc-length` setting in `pyproject.toml`). If the summary
+  does not fit, shorten the wording rather than wrapping to a second
+  line.
 - Prefer flat over nested, explicit over clever.
 - Write straightforward code; do not add defensive checks for unlikely
   edge cases.
diff --git a/docs/architecture/adp_implementation.md b/docs/architecture/adp_implementation.md
new file mode 100644
index 000000000..4d66e0b74
--- /dev/null
+++ b/docs/architecture/adp_implementation.md
@@ -0,0 +1,321 @@
+# ADP Implementation Plan
+
+**Date:** 2026-04-12 **Status:** Design approved — awaiting
+implementation
+
+---
+
+## 1. Goal
+
+Extend ADP (Atomic Displacement Parameter) support from the current
+Biso-only implementation to all four CIF-standard types: **Biso**,
+**Uiso**, **Bani**, **Uani**. The design uses type-neutral parameter
+names (`adp_iso`, `adp_11`…`adp_23`) so that switching ADP type is a
+one-line operation on `adp_type` without creating or destroying
+parameters.
+
+---
+
+## 2. Design Summary
+
+### 2.1 Two Sibling Collections on Structure
+
+Following CIF conventions (`_atom_site` + `_atom_site_aniso` are
+separate loops), the structure owns two sibling collections:
+
+```
+Structure
+├── cell              (CategoryItem)
+├── space_group       (CategoryItem)
+├── atom_sites        (CategoryCollection of AtomSite)
+└── atom_site_aniso   (CategoryCollection of AtomSiteAniso)
+```
+
+Every atom always has an entry in both collections, kept in sync by
+`Structure._update_categories()`. This eliminates conditional existence
+checks throughout the codebase.
+
+### 2.2 Type-Neutral Parameter Names
+
+Parameters on `AtomSite` and `AtomSiteAniso` use type-neutral names
+whose physical meaning is determined by `atom_site.adp_type`:
+
+| Parameter  | Location        | CIF names (order depends on `adp_type`)                  |
+| ---------- | --------------- | -------------------------------------------------------- |
+| `adp_type` | `AtomSite`      | `_atom_site.adp_type`                                    |
+| `adp_iso`  | `AtomSite`      | `_atom_site.B_iso_or_equiv`, `_atom_site.U_iso_or_equiv` |
+| `adp_11`   | `AtomSiteAniso` | `_atom_site_aniso.B_11`, `_atom_site_aniso.U_11`         |
+| `adp_22`   | `AtomSiteAniso` | `_atom_site_aniso.B_22`, `_atom_site_aniso.U_22`         |
+| `adp_33`   | `AtomSiteAniso` | `_atom_site_aniso.B_33`, `_atom_site_aniso.U_33`         |
+| `adp_12`   | `AtomSiteAniso` | `_atom_site_aniso.B_12`, `_atom_site_aniso.U_12`         |
+| `adp_13`   | `AtomSiteAniso` | `_atom_site_aniso.B_13`, `_atom_site_aniso.U_13`         |
+| `adp_23`   | `AtomSiteAniso` | `_atom_site_aniso.B_23`, `_atom_site_aniso.U_23`         |
+
+### 2.3 Dual CIF Names — Static Read, Reordered Write
+
+Each parameter's `CifHandler` carries both CIF name variants. The
+existing infrastructure handles this:
+
+- **Reading (deserialization):** `param_from_cif()` and
+  `category_collection_from_cif()` iterate `_cif_handler.names` and stop
+  at the first match. A CIF file with `_atom_site.U_iso_or_equiv` is
+  read correctly regardless of name order.
+- **Writing (serialization):** `param_to_cif()` and
+  `category_collection_to_cif()` always use `names[0]`. The `adp_type`
+  setter reorders the `names` list so that the correct CIF tag is
+  emitted first.
+
+Example — when `adp_type` changes from `'Biso'` to `'Uiso'`:
+
+```python
+# adp_type setter reorders CIF names on adp_iso
+self._adp_iso._cif_handler._names = [
+    '_atom_site.U_iso_or_equiv',
+    '_atom_site.B_iso_or_equiv',
+]
+```
+
+No new core CIF infrastructure is needed.
+
+### 2.4 ADP Type Enum
+
+```python
+class AdpTypeEnum(str, Enum):
+    BISO = 'Biso'
+    UISO = 'Uiso'
+    BANI = 'Bani'
+    UANI = 'Uani'
+```
+
+`adp_type` on `AtomSite` is a `StringDescriptor` validated by
+`MembershipValidator(allowed=...)` using all four enum values.
+
+### 2.5 Auto-Conversion on Type Switch
+
+Setting `adp_type` triggers value conversion. The physics:
+
+- **B ↔ U (isotropic):** `B = 8π²U`
+- **Iso → Ani:** diagonal `adp_11 = adp_22 = adp_33 = adp_iso`,
+  off-diagonal `adp_12 = adp_13 = adp_23 = 0`
+- **Ani → Iso:** `adp_iso = (adp_11 + adp_22 + adp_33) / 3`
+
+The `adp_type` setter on `AtomSite` performs the conversion and updates
+both the isotropic parameter and the aniso parameters on the sibling
+collection.
+
+### 2.6 Collection Sync via `_update_categories()`
+
+`Structure._update_categories()` reconciles the two collections:
+
+| Event                              | Sync action                                               |
+| ---------------------------------- | --------------------------------------------------------- |
+| Atom added to `atom_sites`         | Create matching `AtomSiteAniso` entry with defaults (0.0) |
+| Atom removed from `atom_sites`     | Remove matching `AtomSiteAniso` entry                     |
+| Atom label renamed in `atom_sites` | Rekey the matching `AtomSiteAniso` entry                  |
+
+The sync is driven by the dirty flag — any parameter or collection
+change sets `_need_categories_update = True`, and the next
+serialization, plot, or fit call triggers `_update_categories()`.
+
+### 2.7 Inactive Aniso Values
+
+When `adp_type` is `'Biso'` or `'Uiso'`, the aniso parameters exist with
+value `0.0` but are not read by calculators. This avoids introducing
+`None` into the `float`-based `Parameter` system.
+
+---
+
+## 3. User-Facing API
+
+### 3.1 Parameter Access Pattern
+
+Parameters are accessed via the standard two-level pattern:
+
+```python
+# CategoryItem.Parameter
+structure.cell.length_a = 3.88
+
+# CategoryCollection[item_id].Parameter
+structure.atom_sites['Si'].adp_type = 'Biso'
+structure.atom_sites['Si'].adp_iso = 0.47
+structure.atom_site_aniso['Si'].adp_11 = 0.05
+```
+
+### 3.2 Switching ADP Type
+
+```python
+# Switch from Biso to Uiso — auto-converts value
+structure.atom_sites['Si'].adp_type = 'Uiso'
+# adp_iso now holds U_iso value (B / 8π²)
+
+# Switch to anisotropic — seeds diagonal from iso
+structure.atom_sites['Si'].adp_type = 'Uani'
+# atom_site_aniso['Si'].adp_11/22/33 seeded from adp_iso
+# adp_iso recalculated as mean of diagonal
+
+# Switch back to isotropic — collapses tensor to scalar
+structure.atom_sites['Si'].adp_type = 'Biso'
+# adp_iso = mean(adp_11, adp_22, adp_33), converted B→U if needed
+```
+
+### 3.3 Creating Atoms
+
+```python
+# adp_iso replaces the old b_iso keyword
+structure.atom_sites.create(
+    label='Si',
+    type_symbol='Si',
+    fract_x=0.0,
+    fract_y=0.0,
+    fract_z=0.0,
+    adp_type='Biso',
+    adp_iso=0.47,
+)
+# atom_site_aniso['Si'] is auto-created by _update_categories()
+```
+
+### 3.4 CIF Output
+
+```cif
+loop_
+_atom_site.label
+_atom_site.type_symbol
+_atom_site.fract_x
+_atom_site.fract_y
+_atom_site.fract_z
+_atom_site.adp_type
+_atom_site.B_iso_or_equiv
+_atom_site.occupancy
+Si  Si  0.00000000  0.00000000  0.00000000  Biso  0.47000000  1.00000000
+
+loop_
+_atom_site_aniso.label
+_atom_site_aniso.B_11
+_atom_site_aniso.B_22
+_atom_site_aniso.B_33
+_atom_site_aniso.B_12
+_atom_site_aniso.B_13
+_atom_site_aniso.B_23
+Si  0.00000000  0.00000000  0.00000000  0.00000000  0.00000000  0.00000000
+```
+
+When `adp_type = 'Uiso'`, the CIF tag becomes
+`_atom_site.U_iso_or_equiv` and the aniso loop uses
+`_atom_site_aniso.U_*` tags.
+
+---
+
+## 4. Implementation Phases
+
+### Phase 1: Rename `b_iso` → `adp_iso` and Expand `adp_type`
+
+**Files to modify:**
+
+1. **`atom_sites/default.py`** — `AtomSite`:
+   - Rename `_b_iso` Parameter to `_adp_iso` with dual CIF names
+     `['_atom_site.B_iso_or_equiv', '_atom_site.U_iso_or_equiv']`.
+   - Expand `_adp_type` validator to accept all four values from
+     `AdpTypeEnum`.
+   - Add `adp_type` setter logic: reorder CIF names on `_adp_iso`,
+     perform B↔U conversion.
+   - Rename property `b_iso` → `adp_iso`.
+
+2. **`atom_sites/enums.py`** (new) — `AdpTypeEnum` with BISO, UISO,
+   BANI, UANI members plus `default()` and `description()` methods.
+
+3. **Calculator bridges** — update `cryspy.py` and `crysfml.py` to read
+   `atom.adp_iso.value` instead of `atom.b_iso.value`, and pass the
+   correct type based on `atom.adp_type.value`.
+
+4. **CIF data files** — update all `.cif` files in `data/` that
+   reference `b_iso`.
+
+5. **Tutorials** — update all `*.py` scripts that use `b_iso`.
+
+6. **Tests** — update all unit/functional/integration tests.
+
+### Phase 2: Add `AtomSiteAniso` Sibling Collection
+
+**Files to create:**
+
+1. **`atom_site_aniso/`** package under
+   `datablocks/structure/categories/`:
+   - `__init__.py` — imports `AtomSiteAniso` and
+     `AtomSiteAnisoCollection`.
+   - `default.py` — `AtomSiteAniso` (CategoryItem) with `label`
+     (StringDescriptor) and six Parameters (`adp_11`…`adp_23`) each with
+     dual CIF names. `AtomSiteAnisoCollection` (CategoryCollection).
+   - `factory.py` — `AtomSiteAnisoFactory`.
+   - `enums.py` — if needed (likely shared with Phase 1 enum).
+
+2. **`structure/item/base.py`** — add `_atom_site_aniso` attribute and
+   `atom_site_aniso` read-only property on Structure.
+
+3. **`structure/item/base.py`** — override `_update_categories()` to
+   reconcile `atom_sites` and `atom_site_aniso` collections (add
+   missing, remove stale, rekey on label change).
+
+**Files to modify:**
+
+4. **`atom_sites/default.py`** — `adp_type` setter also reorders CIF
+   names on all six aniso parameters (accessed via parent structure's
+   `atom_site_aniso` collection).
+
+5. **Calculator bridges** — when `adp_type` is `'Bani'` or `'Uani'`,
+   read from `atom_site_aniso[label]` instead of `adp_iso`.
+
+6. **CIF serialization** — works automatically (Structure's `as_cif`
+   emits all CategoryCollections found in `vars(self)`).
+
+### Phase 3: ADP Symmetry Constraints
+
+1. **`crystallography.py`** — add symmetry constraint functions for
+   anisotropic ADPs based on space group and Wyckoff position.
+
+2. **`AtomSites._update()`** — call aniso symmetry constraints in
+   addition to coordinate constraints.
+
+---
+
+## 5. Breaking Changes
+
+| Change                                    | Scope                             | Migration                          |
+| ----------------------------------------- | --------------------------------- | ---------------------------------- |
+| `b_iso` → `adp_iso`                       | All code referencing `atom.b_iso` | Mechanical rename (greppable)      |
+| `b_iso=0.5` → `adp_iso=0.5` in `create()` | Tutorials, tests, user scripts    | Mechanical rename                  |
+| New `atom_site_aniso` on Structure        | Structure API surface grows       | Additive — no existing code breaks |
+
+The project is in beta, so no deprecation path is needed.
+
+---
+
+## 6. Design Decisions
+
+### Why type-neutral names (`adp_iso`) instead of type-specific (`b_iso`, `u_iso`)?
+
+With type-specific names, switching ADP type would require
+creating/destroying parameters, migrating constraints and free flags,
+and updating every reference. Type-neutral names make switching a
+one-liner on `adp_type` — the parameter object stays the same, only its
+value and CIF tag change.
+
+### Why always-present aniso collection instead of on-demand?
+
+Conditional existence of `atom_site_aniso` would require guards
+everywhere: serialization, calculators, parameter tables, constraint
+wiring, UI. Always-present with 0.0 defaults eliminates all those
+branches.
+
+### Why sync via `_update_categories()` instead of coupled add/remove?
+
+Loose coupling: `AtomSites` and `AtomSiteAnisoCollection` don't know
+about each other. `Structure` coordinates them at update time. This
+follows the existing dirty-flag pattern and keeps categories
+independent.
+
+### Why reorder `_cif_handler.names` instead of dynamic CIF handler?
+
+The existing serialization/deserialization pipeline uses `names[0]` for
+writing and iterates all names for reading. Reordering the list is a
+2-line operation in the `adp_type` setter with zero core infrastructure
+changes.
diff --git a/docs/architecture/architecture.md b/docs/architecture/architecture.md
index 1615307d1..cd14d099e 100644
--- a/docs/architecture/architecture.md
+++ b/docs/architecture/architecture.md
@@ -149,6 +149,28 @@ def _set_sample_form(self, value: str) -> None:
 
 ### 2.3 CategoryItem and CategoryCollection
 
+**Parameter access pattern.** Users reach any parameter through at most
+two levels of navigation from the datablock:
+
+```python
+# CategoryItem → Parameter
+structure.cell.length_a = 3.88
+experiment.instrument.setup_wavelength = 1.494
+
+# CategoryCollection[item_id] → Parameter
+structure.atom_sites['Si'].adp_iso = 0.47
+experiment.background['10'].y = 170
+```
+
+The general forms are:
+
+- `DATABLOCK.CATEGORY_ITEM.PARAMETER`
+- `DATABLOCK.CATEGORY_COLLECTION[ITEM_ID].PARAMETER`
+
+This two-level convention (category then parameter) is a deliberate
+design constraint. Categories are never nested inside other categories
+(see § 9.7), which keeps the path depth uniform and the API predictable.
+
 | Aspect          | `CategoryItem`                     | `CategoryCollection`                      |
 | --------------- | ---------------------------------- | ----------------------------------------- |
 | CIF analogy     | Single category row                | Loop (table) of rows                      |
@@ -285,18 +307,55 @@ being replaced.
 
 ```shell
 DatablockItem
-└── Structure                       # name, cell, space_group, atom_sites
+└── Structure                       # name, cell, space_group, atom_sites, atom_site_aniso
 ```
 
-A `Structure` contains three categories:
+A `Structure` contains four categories:
 
 - `Cell` — unit cell parameters (`CategoryItem`)
 - `SpaceGroup` — symmetry information (`CategoryItem`)
-- `AtomSites` — atomic positions collection (`CategoryCollection`)
+- `AtomSites` — atomic positions and isotropic ADP
+  (`CategoryCollection`)
+- `AtomSiteAniso` — anisotropic ADP tensor components
+  (`CategoryCollection`)
 
 Symmetry constraints (cell metric, atomic coordinates, ADPs) are applied
 via the `crystallography` module during `_update_categories()`.
 
+### 4.2 Atomic Displacement Parameters (ADP)
+
+ADP support covers four CIF-standard types: **Biso**, **Uiso**,
+**Bani**, **Uani**. The design uses **type-neutral parameter names** so
+that switching type is a one-line operation on `adp_type`.
+
+**Two sibling collections.** Following CIF conventions (`_atom_site` and
+`_atom_site_aniso` are separate loops), isotropic and anisotropic data
+live in separate collections on `Structure`. Every atom always has an
+entry in both collections; when `adp_type` is isotropic, the aniso
+parameters hold `0.0` and are ignored by calculators.
+
+**Type-neutral names.** `atom_site.adp_iso` is the type-neutral
+isotropic ADP parameter. Its physical meaning (B or U) is determined by
+`atom_site.adp_type`. Similarly, `atom_site_aniso.adp_11`…`adp_23` are
+type-neutral tensor components.
+
+**Dual CIF names.** Each parameter's `CifHandler` carries both CIF name
+variants (e.g.
+`['_atom_site.B_iso_or_equiv', '_atom_site.U_iso_or_equiv']`). Reading
+tries each name until a match is found; writing uses `names[0]`. The
+`adp_type` setter reorders the list so the correct tag is emitted.
+
+**Auto-conversion.** Setting `adp_type` triggers value conversion: B ↔ U
+via `B = 8π²U`; iso → ani seeds the diagonal; ani → iso averages the
+diagonal.
+
+**Collection sync.** `Structure._update_categories()` reconciles the two
+collections: adds missing aniso entries, removes stale ones, and rekeys
+on label rename.
+
+See [`adp_implementation.md`](adp_implementation.md) for the full
+implementation plan.
+
 ---
 
 ## 5. Factory System
@@ -400,6 +459,7 @@ from .line_segment import LineSegmentBackground
 | `CellFactory`                | Unit cells             | `Cell`                                                                                                                                                                      |
 | `SpaceGroupFactory`          | Space groups           | `SpaceGroup`                                                                                                                                                                |
 | `AtomSitesFactory`           | Atom sites             | `AtomSites`                                                                                                                                                                 |
+| `AtomSiteAnisoFactory`       | Anisotropic ADPs       | `AtomSiteAnisoCollection`                                                                                                                                                   |
 | `AliasesFactory`             | Parameter aliases      | `Aliases`                                                                                                                                                                   |
 | `ConstraintsFactory`         | Parameter constraints  | `Constraints`                                                                                                                                                               |
 | `FitModeFactory`             | Fit-mode category      | `FitMode`                                                                                                                                                                   |
@@ -572,6 +632,7 @@ line-segment points.
 | `ExcludedRegions`               | `ExcludedRegionsFactory`     |
 | `LinkedPhases`                  | `LinkedPhasesFactory`        |
 | `AtomSites`                     | `AtomSitesFactory`           |
+| `AtomSiteAnisoCollection`       | `AtomSiteAnisoFactory`       |
 | `Aliases`                       | `AliasesFactory`             |
 | `Constraints`                   | `ConstraintsFactory`         |
 | `JointFitExperiments`           | `JointFitExperimentsFactory` |
@@ -583,6 +644,7 @@ line-segment points.
 | `LineSegment`        | `LineSegmentBackground`         |
 | `PolynomialTerm`     | `ChebyshevPolynomialBackground` |
 | `AtomSite`           | `AtomSites`                     |
+| `AtomSiteAniso`      | `AtomSiteAnisoCollection`       |
 | `PdCwlDataPoint`     | `PdCwlData`                     |
 | `PdTofDataPoint`     | `PdTofData`                     |
 | `TotalDataPoint`     | `TotalData`                     |
@@ -806,7 +868,7 @@ project.structures['lbco'].atom_sites.create(
     fract_y=0,
     fract_z=0,
     wyckoff_letter='a',
-    b_iso=0.5,
+    adp_iso=0.5,
     occupancy=0.5,
 )
 
@@ -991,7 +1053,7 @@ Single-type categories (no public `_type` property):
 
 - **Experiment:** `diffrn`, `linked_crystal`, `excluded_regions`,
   `linked_phases`.
-- **Structure:** `cell`, `space_group`, `atom_sites`.
+- **Structure:** `cell`, `space_group`, `atom_sites`, `atom_site_aniso`.
 - **Analysis:** `aliases`, `constraints`.
 
 `fit_mode` has show methods (`show_supported_fit_mode_types()`,
diff --git a/docs/architecture/cryspy-dwf-bug.md b/docs/architecture/cryspy-dwf-bug.md
new file mode 100644
index 000000000..5f475ecc6
--- /dev/null
+++ b/docs/architecture/cryspy-dwf-bug.md
@@ -0,0 +1,126 @@
+# CrysPy Bug: Wrong Rotation Matrix Indices in `calc_power_dwf_aniso`
+
+## Summary
+
+`calc_power_dwf_aniso` in CrysPy 0.7.8 reads the rotation matrix from
+the wrong slice of `reduced_symm_elems`, producing incorrect
+Debye–Waller factors for every anisotropic atom.
+
+## Affected Version
+
+CrysPy **0.7.8** (and likely all versions sharing this code path).
+
+## Location
+
+`cryspy/A_functions_base/debye_waller_factor.py`, function
+`calc_power_dwf_aniso`, around line 177.
+
+## Root Cause
+
+`reduced_symm_elems` has shape `(13, N_symmetry_operations)` with the
+following layout per column:
+
+| Indices | Content                             |
+| ------- | ----------------------------------- |
+| 0–3     | Translation: $b_1, b_2, b_3, b_d$   |
+| 4–12    | Rotation matrix $R$ (row-major 3×3) |
+
+The buggy code extracts the rotation matrix from indices **0–8** (i.e.
+`symm_elems_r[0:9]`), which mixes the translation vector into the
+rotation matrix:
+
+```python
+# BUGGY (current code)
+r_11, r_12, r_13 = symm_elems_r[0], symm_elems_r[1], symm_elems_r[2]
+r_21, r_22, r_23 = symm_elems_r[3], symm_elems_r[4], symm_elems_r[5]
+r_31, r_32, r_33 = symm_elems_r[6], symm_elems_r[7], symm_elems_r[8]
+```
+
+The correct indices are **4–12**:
+
+```python
+# FIXED
+r_11, r_12, r_13 = symm_elems_r[4], symm_elems_r[5], symm_elems_r[6]
+r_21, r_22, r_23 = symm_elems_r[7], symm_elems_r[8], symm_elems_r[9]
+r_31, r_32, r_33 = symm_elems_r[10], symm_elems_r[11], symm_elems_r[12]
+```
+
+For comparison, `calc_pr1` in the same codebase (structure factor phase
+calculation) correctly uses indices 4–12 for the rotation.
+
+## Impact
+
+Every structure-factor calculation that uses anisotropic ADPs produces
+wrong results. The isotropic DWF (`calc_power_dwf_iso`) is unaffected
+and works correctly, so the bug only manifests when anisotropic
+displacement parameters ($B_\text{ani}$ or $U_\text{ani}$) are used.
+
+## Verification
+
+We verified the fix by comparing isotropic and anisotropic calculations
+for the LBCO structure (space group $I\,4/m\,m\,m$) where $B_\text{iso}$
+and the equivalent diagonal anisotropic tensor must give identical
+$|F|^2$ values:
+
+| Metric                      | Buggy code                  | Patched code |
+| --------------------------- | --------------------------- | ------------ | ------------------------------ | ---------------------- |
+| $\max                       | y*\text{iso} - y*\text{ani} | $            | ~11 (first peak: 72.1 vs 61.0) | $1.78 \times 10^{-13}$ |
+| $\chi^2$ (Biso)             | 14.98                       | 14.98        |
+| $\chi^2$ (Bani, equivalent) | 184.10                      | 14.98        |
+
+## Workaround
+
+Monkey-patch at import time (used in EasyDiffraction):
+
+```python
+from cryspy.A_functions_base import debye_waller_factor as _dwf_mod
+
+def _patched_calc_power_dwf_aniso(index_hkl, beta, symm_elems_r, flag_beta=False):
+    b_11, b_22, b_33 = beta[0], beta[1], beta[2]
+    b_12, b_13, b_23 = beta[3], beta[4], beta[5]
+    h, k, l = index_hkl[0], index_hkl[1], index_hkl[2]
+    # Corrected indices: rotation starts at 4, not 0
+    r_11, r_12, r_13 = symm_elems_r[4], symm_elems_r[5], symm_elems_r[6]
+    r_21, r_22, r_23 = symm_elems_r[7], symm_elems_r[8], symm_elems_r[9]
+    r_31, r_32, r_33 = symm_elems_r[10], symm_elems_r[11], symm_elems_r[12]
+    h_s = h * r_11 + k * r_21 + l * r_31
+    k_s = h * r_12 + k * r_22 + l * r_32
+    l_s = h * r_13 + k * r_23 + l * r_33
+    power = (
+        b_11 * np.square(h_s) + b_22 * np.square(k_s) + b_33 * np.square(l_s)
+        + 2.0 * b_12 * h_s * k_s
+        + 2.0 * b_13 * h_s * l_s
+        + 2.0 * b_23 * k_s * l_s
+    )
+    dder = {}
+    if flag_beta:
+        ones_b = np.ones_like(b_11)
+        dder['beta'] = np.stack([
+            ones_b * np.square(h_s),
+            ones_b * np.square(k_s),
+            ones_b * np.square(l_s),
+            ones_b * 2.0 * h_s * k_s,
+            ones_b * 2.0 * h_s * l_s,
+            ones_b * 2.0 * k_s * l_s,
+        ], axis=0)
+    return power, dder
+
+_dwf_mod.calc_power_dwf_aniso = _patched_calc_power_dwf_aniso
+```
+
+## Suggested Fix
+
+In `cryspy/A_functions_base/debye_waller_factor.py`, function
+`calc_power_dwf_aniso`, change:
+
+```diff
+-    r_11, r_12, r_13 = symm_elems_r[0], symm_elems_r[1], symm_elems_r[2]
+-    r_21, r_22, r_23 = symm_elems_r[3], symm_elems_r[4], symm_elems_r[5]
+-    r_31, r_32, r_33 = symm_elems_r[6], symm_elems_r[7], symm_elems_r[8]
++    r_11, r_12, r_13 = symm_elems_r[4], symm_elems_r[5], symm_elems_r[6]
++    r_21, r_22, r_23 = symm_elems_r[7], symm_elems_r[8], symm_elems_r[9]
++    r_31, r_32, r_33 = symm_elems_r[10], symm_elems_r[11], symm_elems_r[12]
+```
+
+The same correction must be applied to the analytical-derivative branch
+of the same function if it shares the same index convention.
diff --git a/docs/architecture/package-structure-full.md b/docs/architecture/package-structure-full.md
index c4bf5b5f1..3f16dadfd 100644
--- a/docs/architecture/package-structure-full.md
+++ b/docs/architecture/package-structure-full.md
@@ -279,11 +279,20 @@
 │   │       └── 🏷️ class Experiments
 │   ├── 📁 structure
 │   │   ├── 📁 categories
+│   │   │   ├── 📁 atom_site_aniso
+│   │   │   │   ├── 📄 __init__.py
+│   │   │   │   ├── 📄 default.py
+│   │   │   │   │   ├── 🏷️ class AtomSiteAniso
+│   │   │   │   │   └── 🏷️ class AtomSiteAnisoCollection
+│   │   │   │   └── 📄 factory.py
+│   │   │   │       └── 🏷️ class AtomSiteAnisoFactory
 │   │   │   ├── 📁 atom_sites
 │   │   │   │   ├── 📄 __init__.py
 │   │   │   │   ├── 📄 default.py
 │   │   │   │   │   ├── 🏷️ class AtomSite
 │   │   │   │   │   └── 🏷️ class AtomSites
+│   │   │   │   ├── 📄 enums.py
+│   │   │   │   │   └── 🏷️ class AdpTypeEnum
 │   │   │   │   └── 📄 factory.py
 │   │   │   │       └── 🏷️ class AtomSitesFactory
 │   │   │   ├── 📁 cell
diff --git a/docs/architecture/package-structure-short.md b/docs/architecture/package-structure-short.md
index 5c570ad9f..3fc6b860e 100644
--- a/docs/architecture/package-structure-short.md
+++ b/docs/architecture/package-structure-short.md
@@ -137,9 +137,14 @@
 │   │   └── 📄 collection.py
 │   ├── 📁 structure
 │   │   ├── 📁 categories
+│   │   │   ├── 📁 atom_site_aniso
+│   │   │   │   ├── 📄 __init__.py
+│   │   │   │   ├── 📄 default.py
+│   │   │   │   └── 📄 factory.py
 │   │   │   ├── 📁 atom_sites
 │   │   │   │   ├── 📄 __init__.py
 │   │   │   │   ├── 📄 default.py
+│   │   │   │   ├── 📄 enums.py
 │   │   │   │   └── 📄 factory.py
 │   │   │   ├── 📁 cell
 │   │   │   │   ├── 📄 __init__.py
diff --git a/docs/docs/tutorials/ed-1.ipynb b/docs/docs/tutorials/ed-1.ipynb
index 604fe72da..22b33c7ce 100644
--- a/docs/docs/tutorials/ed-1.ipynb
+++ b/docs/docs/tutorials/ed-1.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "ab0fa7f5",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Structure Refinement: LBCO, HRPT\n",
@@ -44,7 +44,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Import Library"
@@ -53,7 +53,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -62,7 +62,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Step 1: Define Project"
@@ -71,7 +71,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -81,7 +81,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "source": [
     "## Step 2: Define Crystal Structure"
@@ -90,7 +90,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -101,7 +101,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "7",
+   "id": "8",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -111,7 +111,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "source": [
     "## Step 3: Define Experiment"
@@ -120,7 +120,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -131,7 +131,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "10",
+   "id": "11",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -141,7 +141,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "source": [
     "## Step 4: Perform Analysis (no constraints)"
@@ -150,7 +150,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "12",
+   "id": "13",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -162,7 +162,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "13",
+   "id": "14",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -173,7 +173,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "14",
+   "id": "15",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -183,7 +183,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "15",
+   "id": "16",
    "metadata": {},
    "source": [
     "## Step 5: Perform Analysis (with constraints)"
@@ -192,7 +192,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "16",
+   "id": "17",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -205,11 +205,11 @@
     "# define aliases and then use them to create a constraint.\n",
     "project.analysis.aliases.create(\n",
     "    label='biso_La',\n",
-    "    param=project.structures['lbco'].atom_sites['La'].b_iso,\n",
+    "    param=project.structures['lbco'].atom_sites['La'].adp_iso,\n",
     ")\n",
     "project.analysis.aliases.create(\n",
     "    label='biso_Ba',\n",
-    "    param=project.structures['lbco'].atom_sites['Ba'].b_iso,\n",
+    "    param=project.structures['lbco'].atom_sites['Ba'].adp_iso,\n",
     ")\n",
     "project.analysis.constraints.create(expression='biso_Ba = biso_La')"
    ]
@@ -217,7 +217,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "17",
+   "id": "18",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -229,7 +229,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "18",
+   "id": "19",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -240,7 +240,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "19",
+   "id": "20",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -251,7 +251,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "20",
+   "id": "21",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -262,7 +262,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "21",
+   "id": "22",
    "metadata": {},
    "outputs": [],
    "source": [
diff --git a/docs/docs/tutorials/ed-1.py b/docs/docs/tutorials/ed-1.py
index 3fcd9aab7..fde60b0c9 100644
--- a/docs/docs/tutorials/ed-1.py
+++ b/docs/docs/tutorials/ed-1.py
@@ -80,11 +80,11 @@
 # define aliases and then use them to create a constraint.
 project.analysis.aliases.create(
     label='biso_La',
-    param=project.structures['lbco'].atom_sites['La'].b_iso,
+    param=project.structures['lbco'].atom_sites['La'].adp_iso,
 )
 project.analysis.aliases.create(
     label='biso_Ba',
-    param=project.structures['lbco'].atom_sites['Ba'].b_iso,
+    param=project.structures['lbco'].atom_sites['Ba'].adp_iso,
 )
 project.analysis.constraints.create(expression='biso_Ba = biso_La')
 
diff --git a/docs/docs/tutorials/ed-10.ipynb b/docs/docs/tutorials/ed-10.ipynb
index b0cc149c4..d26ce4db3 100644
--- a/docs/docs/tutorials/ed-10.ipynb
+++ b/docs/docs/tutorials/ed-10.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "dc88a9ac",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Pair Distribution Function: Ni, NPD\n",
@@ -36,7 +36,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Import Library"
@@ -45,7 +45,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -54,7 +54,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Create Project"
@@ -63,7 +63,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -72,7 +72,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "source": [
     "## Add Structure"
@@ -81,7 +81,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -91,7 +91,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "7",
+   "id": "8",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -105,13 +105,13 @@
     "    fract_y=0.0,\n",
     "    fract_z=0.0,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "source": [
     "## Add Experiment"
@@ -120,7 +120,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -130,7 +130,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "10",
+   "id": "11",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -147,7 +147,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -162,7 +162,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "12",
+   "id": "13",
    "metadata": {},
    "source": [
     "## Select Fitting Parameters"
@@ -171,18 +171,18 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "13",
+   "id": "14",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.structures['ni'].cell.length_a.free = True\n",
-    "project.structures['ni'].atom_sites['Ni'].b_iso.free = True"
+    "project.structures['ni'].atom_sites['Ni'].adp_iso.free = True"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "14",
+   "id": "15",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -193,7 +193,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "15",
+   "id": "16",
    "metadata": {},
    "source": [
     "## Run Fitting"
@@ -202,17 +202,18 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "16",
+   "id": "17",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.analysis.fit()\n",
-    "project.analysis.display.fit_results()"
+    "project.analysis.display.fit_results()\n",
+    "project.plotter.plot_param_correlations()"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "17",
+   "id": "18",
    "metadata": {},
    "source": [
     "## Plot Measured vs Calculated"
@@ -221,7 +222,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "18",
+   "id": "19",
    "metadata": {},
    "outputs": [],
    "source": [
diff --git a/docs/docs/tutorials/ed-10.py b/docs/docs/tutorials/ed-10.py
index aafde761b..7586c1fbb 100644
--- a/docs/docs/tutorials/ed-10.py
+++ b/docs/docs/tutorials/ed-10.py
@@ -37,7 +37,7 @@
     fract_y=0.0,
     fract_z=0.0,
     wyckoff_letter='a',
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 
 # %% [markdown]
@@ -70,7 +70,7 @@
 
 # %%
 project.structures['ni'].cell.length_a.free = True
-project.structures['ni'].atom_sites['Ni'].b_iso.free = True
+project.structures['ni'].atom_sites['Ni'].adp_iso.free = True
 
 # %%
 project.experiments['pdf'].linked_phases['ni'].scale.free = True
@@ -83,6 +83,7 @@
 # %%
 project.analysis.fit()
 project.analysis.display.fit_results()
+project.plotter.plot_param_correlations()
 
 # %% [markdown]
 # ## Plot Measured vs Calculated
diff --git a/docs/docs/tutorials/ed-11.ipynb b/docs/docs/tutorials/ed-11.ipynb
index 7aba32c38..9eb951673 100644
--- a/docs/docs/tutorials/ed-11.ipynb
+++ b/docs/docs/tutorials/ed-11.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "9736040b",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Pair Distribution Function: Si, NPD\n",
@@ -33,7 +33,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Import Library"
@@ -42,7 +42,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -51,7 +51,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Create Project"
@@ -60,7 +60,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -69,7 +69,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "source": [
     "## Set Plotting Engine"
@@ -78,7 +78,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -90,7 +90,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "7",
+   "id": "8",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -100,7 +100,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "source": [
     "## Add Structure"
@@ -109,7 +109,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -119,7 +119,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "10",
+   "id": "11",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -134,13 +134,13 @@
     "    fract_y=0,\n",
     "    fract_z=0,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "source": [
     "## Add Experiment"
@@ -149,7 +149,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "12",
+   "id": "13",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -159,7 +159,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "13",
+   "id": "14",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -176,7 +176,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "14",
+   "id": "15",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -192,7 +192,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "15",
+   "id": "16",
    "metadata": {},
    "source": [
     "## Select Fitting Parameters"
@@ -201,19 +201,19 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "16",
+   "id": "17",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.structures['si'].cell.length_a.free = True\n",
-    "project.structures['si'].atom_sites['Si'].b_iso.free = True\n",
+    "project.structures['si'].atom_sites['Si'].adp_iso.free = True\n",
     "experiment.linked_phases['si'].scale.free = True"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "17",
+   "id": "18",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -225,7 +225,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "18",
+   "id": "19",
    "metadata": {},
    "source": [
     "## Run Fitting"
@@ -234,17 +234,18 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "19",
+   "id": "20",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.analysis.fit()\n",
-    "project.analysis.display.fit_results()"
+    "project.analysis.display.fit_results()\n",
+    "project.plotter.plot_param_correlations()"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "20",
+   "id": "21",
    "metadata": {},
    "source": [
     "## Plot Measured vs Calculated"
@@ -253,7 +254,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "21",
+   "id": "22",
    "metadata": {},
    "outputs": [],
    "source": [
diff --git a/docs/docs/tutorials/ed-11.py b/docs/docs/tutorials/ed-11.py
index 24d7795e8..795c31bfe 100644
--- a/docs/docs/tutorials/ed-11.py
+++ b/docs/docs/tutorials/ed-11.py
@@ -47,7 +47,7 @@
     fract_y=0,
     fract_z=0,
     wyckoff_letter='a',
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 
 # %% [markdown]
@@ -81,7 +81,7 @@
 
 # %%
 project.structures['si'].cell.length_a.free = True
-project.structures['si'].atom_sites['Si'].b_iso.free = True
+project.structures['si'].atom_sites['Si'].adp_iso.free = True
 experiment.linked_phases['si'].scale.free = True
 
 # %%
@@ -96,6 +96,7 @@
 # %%
 project.analysis.fit()
 project.analysis.display.fit_results()
+project.plotter.plot_param_correlations()
 
 # %% [markdown]
 # ## Plot Measured vs Calculated
diff --git a/docs/docs/tutorials/ed-12.ipynb b/docs/docs/tutorials/ed-12.ipynb
index 75d6c515c..0f4be8f4e 100644
--- a/docs/docs/tutorials/ed-12.ipynb
+++ b/docs/docs/tutorials/ed-12.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "44960a4c",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Pair Distribution Function: NaCl, XRD\n",
@@ -36,7 +36,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Import Library"
@@ -45,7 +45,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -54,7 +54,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Create Project"
@@ -63,7 +63,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -72,7 +72,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "source": [
     "## Set Plotting Engine"
@@ -81,7 +81,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -93,7 +93,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "7",
+   "id": "8",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -104,7 +104,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "source": [
     "## Add Structure"
@@ -113,7 +113,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -123,7 +123,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "10",
+   "id": "11",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -137,7 +137,7 @@
     "    fract_y=0,\n",
     "    fract_z=0,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=1.0,\n",
+    "    adp_iso=1.0,\n",
     ")\n",
     "project.structures['nacl'].atom_sites.create(\n",
     "    label='Cl',\n",
@@ -146,13 +146,13 @@
     "    fract_y=0.5,\n",
     "    fract_z=0.5,\n",
     "    wyckoff_letter='b',\n",
-    "    b_iso=1.0,\n",
+    "    adp_iso=1.0,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "source": [
     "## Add Experiment"
@@ -161,7 +161,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "12",
+   "id": "13",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -171,7 +171,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "13",
+   "id": "14",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -188,7 +188,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "14",
+   "id": "15",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -198,7 +198,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "15",
+   "id": "16",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -208,7 +208,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "16",
+   "id": "17",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -218,7 +218,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "17",
+   "id": "18",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -233,7 +233,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "18",
+   "id": "19",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -242,7 +242,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "19",
+   "id": "20",
    "metadata": {},
    "source": [
     "## Select Fitting Parameters"
@@ -251,19 +251,19 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "20",
+   "id": "21",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.structures['nacl'].cell.length_a.free = True\n",
-    "project.structures['nacl'].atom_sites['Na'].b_iso.free = True\n",
-    "project.structures['nacl'].atom_sites['Cl'].b_iso.free = True"
+    "project.structures['nacl'].atom_sites['Na'].adp_iso.free = True\n",
+    "project.structures['nacl'].atom_sites['Cl'].adp_iso.free = True"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "21",
+   "id": "22",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -274,7 +274,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "22",
+   "id": "23",
    "metadata": {},
    "source": [
     "## Run Fitting"
@@ -283,17 +283,18 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "23",
+   "id": "24",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.analysis.fit()\n",
-    "project.analysis.display.fit_results()"
+    "project.analysis.display.fit_results()\n",
+    "project.plotter.plot_param_correlations()"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "24",
+   "id": "25",
    "metadata": {},
    "source": [
     "## Plot Measured vs Calculated"
@@ -302,7 +303,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "25",
+   "id": "26",
    "metadata": {},
    "outputs": [],
    "source": [
diff --git a/docs/docs/tutorials/ed-12.py b/docs/docs/tutorials/ed-12.py
index d14c42fe1..e6d4d94fa 100644
--- a/docs/docs/tutorials/ed-12.py
+++ b/docs/docs/tutorials/ed-12.py
@@ -50,7 +50,7 @@
     fract_y=0,
     fract_z=0,
     wyckoff_letter='a',
-    b_iso=1.0,
+    adp_iso=1.0,
 )
 project.structures['nacl'].atom_sites.create(
     label='Cl',
@@ -59,7 +59,7 @@
     fract_y=0.5,
     fract_z=0.5,
     wyckoff_letter='b',
-    b_iso=1.0,
+    adp_iso=1.0,
 )
 
 # %% [markdown]
@@ -103,8 +103,8 @@
 
 # %%
 project.structures['nacl'].cell.length_a.free = True
-project.structures['nacl'].atom_sites['Na'].b_iso.free = True
-project.structures['nacl'].atom_sites['Cl'].b_iso.free = True
+project.structures['nacl'].atom_sites['Na'].adp_iso.free = True
+project.structures['nacl'].atom_sites['Cl'].adp_iso.free = True
 
 # %%
 project.experiments['xray_pdf'].linked_phases['nacl'].scale.free = True
@@ -117,6 +117,7 @@
 # %%
 project.analysis.fit()
 project.analysis.display.fit_results()
+project.plotter.plot_param_correlations()
 
 # %% [markdown]
 # ## Plot Measured vs Calculated
diff --git a/docs/docs/tutorials/ed-13.ipynb b/docs/docs/tutorials/ed-13.ipynb
index 254d49e00..2794df54f 100644
--- a/docs/docs/tutorials/ed-13.ipynb
+++ b/docs/docs/tutorials/ed-13.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "1ac207fe",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Fitting Powder Diffraction data\n",
@@ -55,7 +55,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -67,7 +67,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -76,7 +76,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## 📘 Introduction: Simple Reference Fit – Si\n",
@@ -103,7 +103,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -115,7 +115,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -124,7 +124,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "source": [
     "You can set the title and description of the project to provide\n",
@@ -136,7 +136,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "7",
+   "id": "8",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -146,7 +146,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "source": [
     "### 🔬 Create an Experiment\n",
@@ -159,7 +159,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -171,7 +171,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "10",
+   "id": "11",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -182,7 +182,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "source": [
     "Uncomment the following cell if your data reduction failed and the\n",
@@ -196,7 +196,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "12",
+   "id": "13",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -205,7 +205,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "13",
+   "id": "14",
    "metadata": {},
    "source": [
     "Now we can create the experiment and load the measured data. In this\n",
@@ -217,7 +217,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "14",
+   "id": "15",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -228,7 +228,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "15",
+   "id": "16",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -243,7 +243,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "16",
+   "id": "17",
    "metadata": {},
    "source": [
     "#### Inspect Measured Data\n",
@@ -259,7 +259,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "17",
+   "id": "18",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -273,7 +273,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "18",
+   "id": "19",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -284,7 +284,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "19",
+   "id": "20",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -296,7 +296,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "20",
+   "id": "21",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -305,7 +305,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "21",
+   "id": "22",
    "metadata": {},
    "source": [
     "If you zoom in on the highest TOF peak (around 120,000 μs), you will\n",
@@ -328,7 +328,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "22",
+   "id": "23",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -339,7 +339,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "23",
+   "id": "24",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -349,7 +349,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "24",
+   "id": "25",
    "metadata": {},
    "source": [
     "To visualize the effect of excluding the high TOF region, we can plot\n",
@@ -360,7 +360,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "25",
+   "id": "26",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -369,7 +369,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "26",
+   "id": "27",
    "metadata": {},
    "source": [
     "#### Set Instrument Parameters\n",
@@ -392,7 +392,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "27",
+   "id": "28",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -403,7 +403,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "28",
+   "id": "29",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -417,7 +417,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "29",
+   "id": "30",
    "metadata": {},
    "source": [
     "Before proceeding, let's take a quick look at the concept of\n",
@@ -437,7 +437,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "30",
+   "id": "31",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -446,7 +446,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "31",
+   "id": "32",
    "metadata": {},
    "source": [
     "The `value` attribute represents the current value of the parameter as\n",
@@ -460,7 +460,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "32",
+   "id": "33",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -469,7 +469,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "33",
+   "id": "34",
    "metadata": {},
    "source": [
     "Note that to set the value of the parameter, you can simply assign a\n",
@@ -479,7 +479,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "34",
+   "id": "35",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -490,15 +490,14 @@
   },
   {
    "cell_type": "markdown",
-   "id": "35",
+   "id": "36",
    "metadata": {},
    "source": [
     "#### Set Peak Profile Parameters\n",
     "\n",
     "The next set of parameters is needed to define the peak profile used\n",
     "in the fitting process. The peak profile describes the shape of the\n",
-    "diffraction peaks. They include parameters for the broadening and\n",
-    "asymmetry of the peaks.\n",
+    "diffraction peaks.\n",
     "\n",
     "There are several commonly used peak profile functions:\n",
     "- **Gaussian**: Describes peaks with a symmetric bell-shaped curve,\n",
@@ -532,7 +531,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "36",
+   "id": "37",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -543,23 +542,23 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "37",
+   "id": "38",
    "metadata": {},
    "outputs": [],
    "source": [
-    "project_1.experiments['sim_si'].peak_profile_type = 'pseudo-voigt * ikeda-carpenter'\n",
+    "project_1.experiments['sim_si'].peak_profile_type = 'jorgensen'\n",
     "project_1.experiments['sim_si'].peak.broad_gauss_sigma_0 = 69498\n",
     "project_1.experiments['sim_si'].peak.broad_gauss_sigma_1 = -55578\n",
     "project_1.experiments['sim_si'].peak.broad_gauss_sigma_2 = 14560\n",
-    "project_1.experiments['sim_si'].peak.broad_mix_beta_0 = 0.0019\n",
-    "project_1.experiments['sim_si'].peak.broad_mix_beta_1 = 0.0137\n",
-    "project_1.experiments['sim_si'].peak.asym_alpha_0 = -0.0055\n",
-    "project_1.experiments['sim_si'].peak.asym_alpha_1 = 0.0147"
+    "project_1.experiments['sim_si'].peak.exp_decay_beta_0 = 0.0019\n",
+    "project_1.experiments['sim_si'].peak.exp_decay_beta_1 = 0.0137\n",
+    "project_1.experiments['sim_si'].peak.exp_rise_alpha_0 = -0.0055\n",
+    "project_1.experiments['sim_si'].peak.exp_rise_alpha_1 = 0.0147"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "38",
+   "id": "39",
    "metadata": {},
    "source": [
     "#### Set Background\n",
@@ -594,7 +593,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "39",
+   "id": "40",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -605,7 +604,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "40",
+   "id": "41",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -621,7 +620,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "41",
+   "id": "42",
    "metadata": {},
    "source": [
     "### 🧩 Create a Structure – Si\n",
@@ -664,7 +663,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "42",
+   "id": "43",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -674,7 +673,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "43",
+   "id": "44",
    "metadata": {},
    "source": [
     "```\n",
@@ -706,7 +705,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "44",
+   "id": "45",
    "metadata": {},
    "source": [
     "As with adding the experiment in the previous step, we will create a\n",
@@ -716,7 +715,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "45",
+   "id": "46",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -727,7 +726,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "46",
+   "id": "47",
    "metadata": {},
    "source": [
     "#### Add Structure"
@@ -736,7 +735,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "47",
+   "id": "48",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -745,7 +744,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "48",
+   "id": "49",
    "metadata": {},
    "source": [
     "#### Set Space Group"
@@ -753,7 +752,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "49",
+   "id": "50",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -764,7 +763,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "50",
+   "id": "51",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -774,7 +773,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "51",
+   "id": "52",
    "metadata": {},
    "source": [
     "#### Set Lattice Parameters"
@@ -782,7 +781,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "52",
+   "id": "53",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -793,7 +792,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "53",
+   "id": "54",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -802,7 +801,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "54",
+   "id": "55",
    "metadata": {},
    "source": [
     "#### Set Atom Sites"
@@ -810,7 +809,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "55",
+   "id": "56",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -821,7 +820,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "56",
+   "id": "57",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -832,13 +831,13 @@
     "    fract_y=0,\n",
     "    fract_z=0,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.89,\n",
+    "    adp_iso=0.89,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "57",
+   "id": "58",
    "metadata": {},
    "source": [
     "### 🔗 Assign Structure to Experiment\n",
@@ -851,7 +850,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "58",
+   "id": "59",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -862,7 +861,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "59",
+   "id": "60",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -871,7 +870,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "60",
+   "id": "61",
    "metadata": {},
    "source": [
     "### 🚀 Analyze and Fit the Data\n",
@@ -893,7 +892,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "61",
+   "id": "62",
    "metadata": {
     "title": "**Reminder:**"
    },
@@ -910,7 +909,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "62",
+   "id": "63",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -920,7 +919,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "63",
+   "id": "64",
    "metadata": {},
    "source": [
     "#### Set Fit Parameters\n",
@@ -943,7 +942,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "64",
+   "id": "65",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -955,15 +954,15 @@
     "project_1.experiments['sim_si'].peak.broad_gauss_sigma_0.free = True\n",
     "project_1.experiments['sim_si'].peak.broad_gauss_sigma_1.free = True\n",
     "project_1.experiments['sim_si'].peak.broad_gauss_sigma_2.free = True\n",
-    "project_1.experiments['sim_si'].peak.broad_mix_beta_0.free = True\n",
-    "project_1.experiments['sim_si'].peak.broad_mix_beta_1.free = True\n",
-    "project_1.experiments['sim_si'].peak.asym_alpha_0.free = True\n",
-    "project_1.experiments['sim_si'].peak.asym_alpha_1.free = True"
+    "project_1.experiments['sim_si'].peak.exp_decay_beta_0.free = True\n",
+    "project_1.experiments['sim_si'].peak.exp_decay_beta_1.free = True\n",
+    "project_1.experiments['sim_si'].peak.exp_rise_alpha_0.free = True\n",
+    "project_1.experiments['sim_si'].peak.exp_rise_alpha_1.free = True"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "65",
+   "id": "66",
    "metadata": {},
    "source": [
     "#### Show Free Parameters\n",
@@ -974,7 +973,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "66",
+   "id": "67",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -988,7 +987,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "67",
+   "id": "68",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -997,7 +996,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "68",
+   "id": "69",
    "metadata": {},
    "source": [
     "#### Visualize Diffraction Patterns\n",
@@ -1013,7 +1012,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "69",
+   "id": "70",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1022,7 +1021,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "70",
+   "id": "71",
    "metadata": {},
    "source": [
     "#### Run Fitting\n",
@@ -1033,7 +1032,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "71",
+   "id": "72",
    "metadata": {},
    "source": [
     "📖 See\n",
@@ -1044,7 +1043,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "72",
+   "id": "73",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1054,7 +1053,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "73",
+   "id": "74",
    "metadata": {},
    "source": [
     "#### Check Fit Results\n",
@@ -1073,7 +1072,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "74",
+   "id": "75",
    "metadata": {},
    "source": [
     "#### Visualize Fit Results\n",
@@ -1087,7 +1086,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "75",
+   "id": "76",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1096,7 +1095,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "76",
+   "id": "77",
    "metadata": {},
    "source": [
     "#### TOF vs d-spacing\n",
@@ -1130,7 +1129,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "77",
+   "id": "78",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1139,7 +1138,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "78",
+   "id": "79",
    "metadata": {},
    "source": [
     "As you can see, the calculated diffraction pattern now matches the\n",
@@ -1165,7 +1164,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "79",
+   "id": "80",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1174,7 +1173,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "80",
+   "id": "81",
    "metadata": {},
    "source": [
     "## 💪 Exercise: Complex Fit – LBCO\n",
@@ -1195,7 +1194,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "81",
+   "id": "82",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -1203,7 +1202,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "82",
+   "id": "83",
    "metadata": {},
    "source": [
     "You can use the same approach as in the previous part of the notebook,\n",
@@ -1212,7 +1211,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "83",
+   "id": "84",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -1221,7 +1220,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "84",
+   "id": "85",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1232,7 +1231,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "85",
+   "id": "86",
    "metadata": {},
    "source": [
     "### 🔬 Exercise 2: Define an Experiment\n",
@@ -1245,7 +1244,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "86",
+   "id": "87",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -1253,7 +1252,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "87",
+   "id": "88",
    "metadata": {},
    "source": [
     "You can use the same approach as in the previous part of the notebook,\n",
@@ -1262,7 +1261,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "88",
+   "id": "89",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -1271,7 +1270,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "89",
+   "id": "90",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1294,7 +1293,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "90",
+   "id": "91",
    "metadata": {},
    "source": [
     "#### Exercise 2.1: Inspect Measured Data\n",
@@ -1306,7 +1305,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "91",
+   "id": "92",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -1314,7 +1313,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "92",
+   "id": "93",
    "metadata": {},
    "source": [
     "You can use the `plot_meas` method of the project to visualize the\n",
@@ -1325,7 +1324,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "93",
+   "id": "94",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -1334,7 +1333,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "94",
+   "id": "95",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1348,7 +1347,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "95",
+   "id": "96",
    "metadata": {},
    "source": [
     "#### Exercise 2.2: Set Instrument Parameters\n",
@@ -1358,7 +1357,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "96",
+   "id": "97",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -1366,7 +1365,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "97",
+   "id": "98",
    "metadata": {},
    "source": [
     "Use the values from the data reduction process for the LBCO and\n",
@@ -1375,7 +1374,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "98",
+   "id": "99",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -1384,7 +1383,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "99",
+   "id": "100",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1398,7 +1397,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "100",
+   "id": "101",
    "metadata": {},
    "source": [
     "#### Exercise 2.3: Set Peak Profile Parameters\n",
@@ -1408,7 +1407,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "101",
+   "id": "102",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -1416,7 +1415,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "102",
+   "id": "103",
    "metadata": {},
    "source": [
     "Use the values from the\n",
@@ -1428,7 +1427,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "103",
+   "id": "104",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -1437,25 +1436,25 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "104",
+   "id": "105",
    "metadata": {},
    "outputs": [],
    "source": [
     "# # Create a reference to the peak profile parameters from the Si\n",
     "sim_si_peak = project_1.experiments['sim_si'].peak\n",
-    "project_2.experiments['sim_lbco'].peak_profile_type = 'pseudo-voigt * ikeda-carpenter'\n",
+    "project_2.experiments['sim_lbco'].peak_profile_type = 'jorgensen'\n",
     "project_2.experiments['sim_lbco'].peak.broad_gauss_sigma_0 = sim_si_peak.broad_gauss_sigma_0.value\n",
     "project_2.experiments['sim_lbco'].peak.broad_gauss_sigma_1 = sim_si_peak.broad_gauss_sigma_1.value\n",
     "project_2.experiments['sim_lbco'].peak.broad_gauss_sigma_2 = sim_si_peak.broad_gauss_sigma_2.value\n",
-    "project_2.experiments['sim_lbco'].peak.broad_mix_beta_0 = sim_si_peak.broad_mix_beta_0.value\n",
-    "project_2.experiments['sim_lbco'].peak.broad_mix_beta_1 = sim_si_peak.broad_mix_beta_1.value\n",
-    "project_2.experiments['sim_lbco'].peak.asym_alpha_0 = sim_si_peak.asym_alpha_0.value\n",
-    "project_2.experiments['sim_lbco'].peak.asym_alpha_1 = sim_si_peak.asym_alpha_1.value"
+    "project_2.experiments['sim_lbco'].peak.exp_decay_beta_0 = sim_si_peak.exp_decay_beta_0.value\n",
+    "project_2.experiments['sim_lbco'].peak.exp_decay_beta_1 = sim_si_peak.exp_decay_beta_1.value\n",
+    "project_2.experiments['sim_lbco'].peak.exp_rise_alpha_0 = sim_si_peak.exp_rise_alpha_0.value\n",
+    "project_2.experiments['sim_lbco'].peak.exp_rise_alpha_1 = sim_si_peak.exp_rise_alpha_1.value"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "105",
+   "id": "106",
    "metadata": {},
    "source": [
     "#### Exercise 2.4: Set Background\n",
@@ -1466,7 +1465,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "106",
+   "id": "107",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -1474,7 +1473,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "107",
+   "id": "108",
    "metadata": {},
    "source": [
     "Use the same approach as in the previous part of the notebook, but\n",
@@ -1485,7 +1484,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "108",
+   "id": "109",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -1494,7 +1493,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "109",
+   "id": "110",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1510,7 +1509,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "110",
+   "id": "111",
    "metadata": {},
    "source": [
     "### 🧩 Exercise 3: Define a Structure – LBCO\n",
@@ -1526,7 +1525,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "111",
+   "id": "112",
    "metadata": {},
    "source": [
     "```\n",
@@ -1561,7 +1560,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "112",
+   "id": "113",
    "metadata": {},
    "source": [
     "Note that the `occupancy` of the La and Ba atoms is 0.5\n",
@@ -1591,7 +1590,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "113",
+   "id": "114",
    "metadata": {},
    "source": [
     "#### Exercise 3.1: Create Structure\n",
@@ -1602,7 +1601,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "114",
+   "id": "115",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -1610,7 +1609,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "115",
+   "id": "116",
    "metadata": {},
    "source": [
     "You can use the same approach as in the previous part of the notebook,\n",
@@ -1620,7 +1619,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "116",
+   "id": "117",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -1629,7 +1628,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "117",
+   "id": "118",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1638,7 +1637,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "118",
+   "id": "119",
    "metadata": {},
    "source": [
     "#### Exercise 3.2: Set Space Group\n",
@@ -1648,7 +1647,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "119",
+   "id": "120",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -1656,7 +1655,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "120",
+   "id": "121",
    "metadata": {},
    "source": [
     "Use the space group name and IT coordinate system code from the CIF\n",
@@ -1665,7 +1664,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "121",
+   "id": "122",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -1674,7 +1673,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "122",
+   "id": "123",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1684,7 +1683,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "123",
+   "id": "124",
    "metadata": {},
    "source": [
     "#### Exercise 3.3: Set Lattice Parameters\n",
@@ -1694,7 +1693,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "124",
+   "id": "125",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -1702,7 +1701,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "125",
+   "id": "126",
    "metadata": {},
    "source": [
     "Use the lattice parameters from the CIF data."
@@ -1710,7 +1709,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "126",
+   "id": "127",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -1719,7 +1718,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "127",
+   "id": "128",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1728,7 +1727,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "128",
+   "id": "129",
    "metadata": {},
    "source": [
     "#### Exercise 3.4: Set Atom Sites\n",
@@ -1738,7 +1737,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "129",
+   "id": "130",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -1746,7 +1745,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "130",
+   "id": "131",
    "metadata": {},
    "source": [
     "Use the atom sites from the CIF data. You can use the `add` method of\n",
@@ -1755,7 +1754,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "131",
+   "id": "132",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -1764,7 +1763,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "132",
+   "id": "133",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1775,7 +1774,7 @@
     "    fract_y=0,\n",
     "    fract_z=0,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.95,\n",
+    "    adp_iso=0.95,\n",
     "    occupancy=0.5,\n",
     ")\n",
     "project_2.structures['lbco'].atom_sites.create(\n",
@@ -1785,7 +1784,7 @@
     "    fract_y=0,\n",
     "    fract_z=0,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.95,\n",
+    "    adp_iso=0.95,\n",
     "    occupancy=0.5,\n",
     ")\n",
     "project_2.structures['lbco'].atom_sites.create(\n",
@@ -1795,7 +1794,7 @@
     "    fract_y=0.5,\n",
     "    fract_z=0.5,\n",
     "    wyckoff_letter='b',\n",
-    "    b_iso=0.80,\n",
+    "    adp_iso=0.80,\n",
     ")\n",
     "project_2.structures['lbco'].atom_sites.create(\n",
     "    label='O',\n",
@@ -1804,13 +1803,13 @@
     "    fract_y=0.5,\n",
     "    fract_z=0.5,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=1.66,\n",
+    "    adp_iso=1.66,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "133",
+   "id": "134",
    "metadata": {},
    "source": [
     "### 🔗 Exercise 4: Assign Structure to Experiment\n",
@@ -1820,7 +1819,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "134",
+   "id": "135",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -1828,7 +1827,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "135",
+   "id": "136",
    "metadata": {},
    "source": [
     "Use the `linked_phases` attribute of the experiment to link the\n",
@@ -1837,7 +1836,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "136",
+   "id": "137",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -1846,7 +1845,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "137",
+   "id": "138",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1855,7 +1854,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "138",
+   "id": "139",
    "metadata": {},
    "source": [
     "### 🚀 Exercise 5: Analyze and Fit the Data\n",
@@ -1868,7 +1867,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "139",
+   "id": "140",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -1876,7 +1875,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "140",
+   "id": "141",
    "metadata": {},
    "source": [
     "You can start with the scale factor and the background points, as in\n",
@@ -1885,7 +1884,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "141",
+   "id": "142",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -1894,7 +1893,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "142",
+   "id": "143",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1906,7 +1905,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "143",
+   "id": "144",
    "metadata": {},
    "source": [
     "#### Exercise 5.2: Run Fitting\n",
@@ -1917,7 +1916,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "144",
+   "id": "145",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -1925,7 +1924,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "145",
+   "id": "146",
    "metadata": {},
    "source": [
     "Use the `plot_meas_vs_calc` method of the project to visualize the\n",
@@ -1936,7 +1935,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "146",
+   "id": "147",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -1945,7 +1944,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "147",
+   "id": "148",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1957,7 +1956,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "148",
+   "id": "149",
    "metadata": {},
    "source": [
     "#### Exercise 5.3: Find the Misfit in the Fit\n",
@@ -1972,7 +1971,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "149",
+   "id": "150",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -1980,7 +1979,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "150",
+   "id": "151",
    "metadata": {},
    "source": [
     "Consider the following options:\n",
@@ -1992,7 +1991,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "151",
+   "id": "152",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -2000,7 +1999,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "152",
+   "id": "153",
    "metadata": {},
    "source": [
     "\n",
@@ -2022,7 +2021,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "153",
+   "id": "154",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2031,7 +2030,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "154",
+   "id": "155",
    "metadata": {},
    "source": [
     "#### Exercise 5.4: Refine the LBCO Lattice Parameter\n",
@@ -2041,7 +2040,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "155",
+   "id": "156",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -2049,7 +2048,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "156",
+   "id": "157",
    "metadata": {},
    "source": [
     "To achieve this, we will set the `free` attribute of the `length_a`\n",
@@ -2064,7 +2063,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "157",
+   "id": "158",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -2073,7 +2072,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "158",
+   "id": "159",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2087,7 +2086,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "159",
+   "id": "160",
    "metadata": {},
    "source": [
     "One of the main goals of this study was to refine the lattice\n",
@@ -2100,7 +2099,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "160",
+   "id": "161",
    "metadata": {},
    "source": [
     "#### Exercise 5.5: Visualize the Fit Results in d-spacing\n",
@@ -2111,7 +2110,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "161",
+   "id": "162",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -2119,7 +2118,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "162",
+   "id": "163",
    "metadata": {},
    "source": [
     "Use the `plot_meas_vs_calc` method of the project and set the\n",
@@ -2128,7 +2127,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "163",
+   "id": "164",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -2137,7 +2136,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "164",
+   "id": "165",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2146,7 +2145,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "165",
+   "id": "166",
    "metadata": {},
    "source": [
     "#### Exercise 5.6: Refine the Peak Profile Parameters\n",
@@ -2166,7 +2165,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "166",
+   "id": "167",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2175,7 +2174,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "167",
+   "id": "168",
    "metadata": {},
    "source": [
     "The peak profile parameters are determined based on both the\n",
@@ -2189,7 +2188,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "168",
+   "id": "169",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -2197,7 +2196,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "169",
+   "id": "170",
    "metadata": {},
    "source": [
     "You can set the `free` attribute of the peak profile parameters to\n",
@@ -2208,7 +2207,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "170",
+   "id": "171",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -2217,17 +2216,17 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "171",
+   "id": "172",
    "metadata": {},
    "outputs": [],
    "source": [
     "project_2.experiments['sim_lbco'].peak.broad_gauss_sigma_0.free = True\n",
     "project_2.experiments['sim_lbco'].peak.broad_gauss_sigma_1.free = True\n",
     "project_2.experiments['sim_lbco'].peak.broad_gauss_sigma_2.free = True\n",
-    "project_2.experiments['sim_lbco'].peak.broad_mix_beta_0.free = True\n",
-    "project_2.experiments['sim_lbco'].peak.broad_mix_beta_1.free = True\n",
-    "project_2.experiments['sim_lbco'].peak.asym_alpha_0.free = True\n",
-    "project_2.experiments['sim_lbco'].peak.asym_alpha_1.free = True\n",
+    "project_2.experiments['sim_lbco'].peak.exp_decay_beta_0.free = True\n",
+    "project_2.experiments['sim_lbco'].peak.exp_decay_beta_1.free = True\n",
+    "project_2.experiments['sim_lbco'].peak.exp_rise_alpha_0.free = True\n",
+    "project_2.experiments['sim_lbco'].peak.exp_rise_alpha_1.free = True\n",
     "\n",
     "project_2.analysis.fit()\n",
     "project_2.analysis.display.fit_results()\n",
@@ -2237,7 +2236,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "172",
+   "id": "173",
    "metadata": {},
    "source": [
     "#### Exercise 5.7: Find Undefined Features\n",
@@ -2249,7 +2248,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "173",
+   "id": "174",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -2257,7 +2256,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "174",
+   "id": "175",
    "metadata": {},
    "source": [
     "While the fit is now significantly better, there are still some\n",
@@ -2269,7 +2268,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "175",
+   "id": "176",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -2278,7 +2277,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "176",
+   "id": "177",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2287,7 +2286,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "177",
+   "id": "178",
    "metadata": {},
    "source": [
     "#### Exercise 5.8: Identify the Cause of the Unexplained Peaks\n",
@@ -2300,7 +2299,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "178",
+   "id": "179",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -2308,7 +2307,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "179",
+   "id": "180",
    "metadata": {},
    "source": [
     "Consider the following options:\n",
@@ -2320,7 +2319,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "180",
+   "id": "181",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -2328,7 +2327,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "181",
+   "id": "182",
    "metadata": {},
    "source": [
     "1. ❌ In principle, this could be the case, as sometimes the presence\n",
@@ -2348,7 +2347,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "182",
+   "id": "183",
    "metadata": {},
    "source": [
     "#### Exercise 5.9: Identify the impurity phase\n",
@@ -2359,7 +2358,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "183",
+   "id": "184",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -2367,7 +2366,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "184",
+   "id": "185",
    "metadata": {},
    "source": [
     "Check the positions of the unexplained peaks in the diffraction\n",
@@ -2377,7 +2376,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "185",
+   "id": "186",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -2385,7 +2384,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "186",
+   "id": "187",
    "metadata": {},
    "source": [
     "The unexplained peaks are likely due to the presence of a small amount\n",
@@ -2400,7 +2399,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "187",
+   "id": "188",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2410,7 +2409,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "188",
+   "id": "189",
    "metadata": {},
    "source": [
     "#### Exercise 5.10: Create a Second Structure – Si as Impurity\n",
@@ -2422,7 +2421,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "189",
+   "id": "190",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -2430,7 +2429,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "190",
+   "id": "191",
    "metadata": {},
    "source": [
     "You can use the same approach as in the previous part of the notebook,\n",
@@ -2440,7 +2439,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "191",
+   "id": "192",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -2449,7 +2448,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "192",
+   "id": "193",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2469,7 +2468,7 @@
     "    fract_y=0,\n",
     "    fract_z=0,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.89,\n",
+    "    adp_iso=0.89,\n",
     ")\n",
     "\n",
     "# Assign Structure to Experiment\n",
@@ -2478,7 +2477,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "193",
+   "id": "194",
    "metadata": {},
    "source": [
     "#### Exercise 5.11: Refine the Scale of the Si Phase\n",
@@ -2491,7 +2490,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "194",
+   "id": "195",
    "metadata": {},
    "source": [
     "**Hint:**"
@@ -2499,7 +2498,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "195",
+   "id": "196",
    "metadata": {},
    "source": [
     "You can use the `plot_meas_vs_calc` method of the project to visualize\n",
@@ -2510,7 +2509,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "196",
+   "id": "197",
    "metadata": {},
    "source": [
     "**Solution:**"
@@ -2519,7 +2518,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "197",
+   "id": "198",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2548,7 +2547,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "198",
+   "id": "199",
    "metadata": {},
    "source": [
     "All previously unexplained peaks are now accounted for in the pattern,\n",
@@ -2571,7 +2570,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "199",
+   "id": "200",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2580,7 +2579,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "200",
+   "id": "201",
    "metadata": {},
    "source": [
     "Finally, we save the project to disk to preserve the current state of\n",
@@ -2590,7 +2589,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "201",
+   "id": "202",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2599,7 +2598,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "202",
+   "id": "203",
    "metadata": {},
    "source": [
     "#### Final Remarks\n",
@@ -2618,7 +2617,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "203",
+   "id": "204",
    "metadata": {},
    "source": [
     "## 🎁 Bonus\n",
diff --git a/docs/docs/tutorials/ed-13.py b/docs/docs/tutorials/ed-13.py
index 20addf9a8..597882801 100644
--- a/docs/docs/tutorials/ed-13.py
+++ b/docs/docs/tutorials/ed-13.py
@@ -488,7 +488,7 @@
     fract_y=0,
     fract_z=0,
     wyckoff_letter='a',
-    b_iso=0.89,
+    adp_iso=0.89,
 )
 
 # %% [markdown]
@@ -1013,7 +1013,7 @@
     fract_y=0,
     fract_z=0,
     wyckoff_letter='a',
-    b_iso=0.95,
+    adp_iso=0.95,
     occupancy=0.5,
 )
 project_2.structures['lbco'].atom_sites.create(
@@ -1023,7 +1023,7 @@
     fract_y=0,
     fract_z=0,
     wyckoff_letter='a',
-    b_iso=0.95,
+    adp_iso=0.95,
     occupancy=0.5,
 )
 project_2.structures['lbco'].atom_sites.create(
@@ -1033,7 +1033,7 @@
     fract_y=0.5,
     fract_z=0.5,
     wyckoff_letter='b',
-    b_iso=0.80,
+    adp_iso=0.80,
 )
 project_2.structures['lbco'].atom_sites.create(
     label='O',
@@ -1042,7 +1042,7 @@
     fract_y=0.5,
     fract_z=0.5,
     wyckoff_letter='c',
-    b_iso=1.66,
+    adp_iso=1.66,
 )
 
 # %% [markdown]
@@ -1385,7 +1385,7 @@
     fract_y=0,
     fract_z=0,
     wyckoff_letter='a',
-    b_iso=0.89,
+    adp_iso=0.89,
 )
 
 # Assign Structure to Experiment
diff --git a/docs/docs/tutorials/ed-14.ipynb b/docs/docs/tutorials/ed-14.ipynb
index 9d2a9c5b0..deef9c1f3 100644
--- a/docs/docs/tutorials/ed-14.ipynb
+++ b/docs/docs/tutorials/ed-14.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "86c9f966",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Structure Refinement: Tb2TiO7, HEiDi\n",
@@ -32,7 +32,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Import Library"
@@ -41,7 +41,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -50,7 +50,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Step 1: Define Project"
@@ -59,7 +59,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -69,7 +69,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "source": [
     "## Step 2: Define Structure"
@@ -78,7 +78,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -89,7 +89,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "7",
+   "id": "8",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -99,7 +99,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -109,7 +109,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -119,29 +119,52 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "10",
+   "id": "11",
    "metadata": {},
    "outputs": [],
    "source": [
-    "structure.atom_sites['Tb'].b_iso = 0.0\n",
-    "structure.atom_sites['Ti'].b_iso = 0.0\n",
-    "structure.atom_sites['O1'].b_iso = 0.0\n",
-    "structure.atom_sites['O2'].b_iso = 0.0"
+    "structure.show_as_cif()"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "outputs": [],
    "source": [
-    "structure.show_as_cif()"
+    "structure.atom_sites['Tb'].adp_type = 'Uiso'\n",
+    "structure.atom_sites['Ti'].adp_type = 'Uiso'\n",
+    "structure.atom_sites['O1'].adp_type = 'Uiso'\n",
+    "structure.atom_sites['O2'].adp_type = 'Uiso'"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "13",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "print(structure.atom_sites.as_cif)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "14",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "structure.atom_sites['Tb'].adp_iso = 0.0\n",
+    "structure.atom_sites['Ti'].adp_iso = 0.0\n",
+    "structure.atom_sites['O1'].adp_iso = 0.0\n",
+    "structure.atom_sites['O2'].adp_iso = 0.0"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "12",
+   "id": "15",
    "metadata": {},
    "source": [
     "## Step 3: Define Experiment"
@@ -150,17 +173,18 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "13",
+   "id": "16",
    "metadata": {},
    "outputs": [],
    "source": [
+    "# Download data file from repository\n",
     "data_path = ed.download_data(id=19, destination='data')"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "14",
+   "id": "17",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -176,17 +200,17 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "15",
+   "id": "18",
    "metadata": {},
    "outputs": [],
    "source": [
-    "experiment = project.experiments['heidi']  # TODO: <heidi (None)>"
+    "experiment = project.experiments['heidi']"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "16",
+   "id": "19",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -197,7 +221,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "17",
+   "id": "20",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -207,26 +231,26 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "18",
+   "id": "21",
    "metadata": {},
    "outputs": [],
    "source": [
-    "experiment.extinction.mosaicity = 29820\n",
-    "experiment.extinction.radius = 30"
+    "experiment.extinction.mosaicity = 35000\n",
+    "experiment.extinction.radius = 10"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "19",
+   "id": "22",
    "metadata": {},
    "source": [
-    "## Step 4: Perform Analysis"
+    "## Step 4: Perform Analysis I (ADP iso)"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "20",
+   "id": "23",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -236,28 +260,37 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "21",
+   "id": "24",
    "metadata": {},
    "outputs": [],
    "source": [
-    "experiment.linked_crystal.scale.free = True\n",
-    "experiment.extinction.radius.free = True"
+    "structure.atom_sites['O1'].fract_x.free = True\n",
+    "\n",
+    "structure.atom_sites['Ti'].occupancy.free = True\n",
+    "structure.atom_sites['O1'].occupancy.free = True\n",
+    "structure.atom_sites['O2'].occupancy.free = True\n",
+    "\n",
+    "structure.atom_sites['Tb'].adp_iso.free = True\n",
+    "structure.atom_sites['Ti'].adp_iso.free = True\n",
+    "structure.atom_sites['O1'].adp_iso.free = True\n",
+    "structure.atom_sites['O2'].adp_iso.free = True"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "22",
+   "id": "25",
    "metadata": {},
    "outputs": [],
    "source": [
-    "experiment.show_as_cif()"
+    "experiment.linked_crystal.scale.free = True\n",
+    "experiment.extinction.radius.free = True"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "23",
+   "id": "26",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -269,7 +302,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "24",
+   "id": "27",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -280,17 +313,17 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "25",
+   "id": "28",
    "metadata": {},
    "outputs": [],
    "source": [
-    "experiment.show_as_cif()"
+    "structure.show_as_cif()"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "26",
+   "id": "29",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -300,7 +333,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "27",
+   "id": "30",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -309,20 +342,100 @@
   },
   {
    "cell_type": "markdown",
-   "id": "28",
+   "id": "31",
    "metadata": {},
    "source": [
-    "## Step 5: Show Project Summary"
+    "## Step 5: Perform Analysis (ADP aniso)"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "29",
+   "id": "32",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "structure.atom_sites['Tb'].adp_type = 'Uani'\n",
+    "structure.atom_sites['Ti'].adp_type = 'Uani'\n",
+    "structure.atom_sites['O1'].adp_type = 'Uani'\n",
+    "# structure.atom_sites['O2'].adp_type = 'Uani'"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "33",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "print(structure.atom_site_aniso.as_cif)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "34",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "structure.atom_site_aniso['Tb'].adp_11.free = True\n",
+    "structure.atom_site_aniso['Tb'].adp_12.free = True\n",
+    "structure.atom_site_aniso['Ti'].adp_11.free = True\n",
+    "structure.atom_site_aniso['Ti'].adp_12.free = True\n",
+    "structure.atom_site_aniso['O1'].adp_11.free = True\n",
+    "structure.atom_site_aniso['O1'].adp_22.free = True\n",
+    "structure.atom_site_aniso['O1'].adp_23.free = True\n",
+    "# structure.atom_site_aniso['O2'].adp_11.free = True"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "35",
    "metadata": {},
    "outputs": [],
    "source": [
-    "project.summary.show_report()"
+    "project.analysis.fit()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "36",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.analysis.display.fit_results()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "37",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.plotter.plot_param_correlations()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "38",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.plotter.plot_meas_vs_calc(expt_name='heidi')"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "39",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "structure.show_as_cif()"
    ]
   }
  ],
diff --git a/docs/docs/tutorials/ed-14.py b/docs/docs/tutorials/ed-14.py
index 22502ecd9..6bf496ff8 100644
--- a/docs/docs/tutorials/ed-14.py
+++ b/docs/docs/tutorials/ed-14.py
@@ -34,18 +34,28 @@
 structure = project.structures['tbti']
 
 # %%
-structure.atom_sites['Tb'].b_iso = 0.0
-structure.atom_sites['Ti'].b_iso = 0.0
-structure.atom_sites['O1'].b_iso = 0.0
-structure.atom_sites['O2'].b_iso = 0.0
+structure.show_as_cif()
 
 # %%
-structure.show_as_cif()
+structure.atom_sites['Tb'].adp_type = 'Uiso'
+structure.atom_sites['Ti'].adp_type = 'Uiso'
+structure.atom_sites['O1'].adp_type = 'Uiso'
+structure.atom_sites['O2'].adp_type = 'Uiso'
+
+# %%
+print(structure.atom_sites.as_cif)
+
+# %%
+structure.atom_sites['Tb'].adp_iso = 0.0
+structure.atom_sites['Ti'].adp_iso = 0.0
+structure.atom_sites['O1'].adp_iso = 0.0
+structure.atom_sites['O2'].adp_iso = 0.0
 
 # %% [markdown]
 # ## Step 3: Define Experiment
 
 # %%
+# Download data file from repository
 data_path = ed.download_data(id=19, destination='data')
 
 # %%
@@ -58,7 +68,7 @@
 )
 
 # %%
-experiment = project.experiments['heidi']  # TODO: <heidi (None)>
+experiment = project.experiments['heidi']
 
 # %%
 experiment.linked_crystal.id = 'tbti'
@@ -68,21 +78,30 @@
 experiment.instrument.setup_wavelength = 0.793
 
 # %%
-experiment.extinction.mosaicity = 29820
-experiment.extinction.radius = 30
+experiment.extinction.mosaicity = 35000
+experiment.extinction.radius = 10
 
 # %% [markdown]
-# ## Step 4: Perform Analysis
+# ## Step 4: Perform Analysis I (ADP iso)
 
 # %%
 project.plotter.plot_meas_vs_calc(expt_name='heidi')
 
 # %%
-experiment.linked_crystal.scale.free = True
-experiment.extinction.radius.free = True
+structure.atom_sites['O1'].fract_x.free = True
+
+structure.atom_sites['Ti'].occupancy.free = True
+structure.atom_sites['O1'].occupancy.free = True
+structure.atom_sites['O2'].occupancy.free = True
+
+structure.atom_sites['Tb'].adp_iso.free = True
+structure.atom_sites['Ti'].adp_iso.free = True
+structure.atom_sites['O1'].adp_iso.free = True
+structure.atom_sites['O2'].adp_iso.free = True
 
 # %%
-experiment.show_as_cif()
+experiment.linked_crystal.scale.free = True
+experiment.extinction.radius.free = True
 
 # %%
 # Start refinement. All parameters, which have standard uncertainties
@@ -94,7 +113,7 @@
 project.analysis.display.fit_results()
 
 # %%
-experiment.show_as_cif()
+structure.show_as_cif()
 
 # %%
 project.experiments.show_names()
@@ -103,7 +122,38 @@
 project.plotter.plot_meas_vs_calc(expt_name='heidi')
 
 # %% [markdown]
-# ## Step 5: Show Project Summary
+# ## Step 5: Perform Analysis (ADP aniso)
+
+# %%
+structure.atom_sites['Tb'].adp_type = 'Uani'
+structure.atom_sites['Ti'].adp_type = 'Uani'
+structure.atom_sites['O1'].adp_type = 'Uani'
+# structure.atom_sites['O2'].adp_type = 'Uani'
 
 # %%
-project.summary.show_report()
+print(structure.atom_site_aniso.as_cif)
+
+# %%
+structure.atom_site_aniso['Tb'].adp_11.free = True
+structure.atom_site_aniso['Tb'].adp_12.free = True
+structure.atom_site_aniso['Ti'].adp_11.free = True
+structure.atom_site_aniso['Ti'].adp_12.free = True
+structure.atom_site_aniso['O1'].adp_11.free = True
+structure.atom_site_aniso['O1'].adp_22.free = True
+structure.atom_site_aniso['O1'].adp_23.free = True
+# structure.atom_site_aniso['O2'].adp_11.free = True
+
+# %%
+project.analysis.fit()
+
+# %%
+project.analysis.display.fit_results()
+
+# %%
+project.plotter.plot_param_correlations()
+
+# %%
+project.plotter.plot_meas_vs_calc(expt_name='heidi')
+
+# %%
+structure.show_as_cif()
diff --git a/docs/docs/tutorials/ed-15.ipynb b/docs/docs/tutorials/ed-15.ipynb
index 12e88c10a..964b988a9 100644
--- a/docs/docs/tutorials/ed-15.ipynb
+++ b/docs/docs/tutorials/ed-15.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "c631fd19",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Structure Refinement: Taurine, SENJU\n",
@@ -32,7 +32,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Import Library"
@@ -41,7 +41,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -50,7 +50,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Step 1: Define Project"
@@ -59,7 +59,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -69,7 +69,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "source": [
     "## Step 2: Define Structure"
@@ -78,7 +78,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -89,7 +89,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "7",
+   "id": "8",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -99,7 +99,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -109,7 +109,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -119,16 +119,16 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "10",
+   "id": "11",
    "metadata": {},
    "outputs": [],
    "source": [
-    "# structure.show_as_cif()"
+    "structure.show_as_cif()"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "source": [
     "## Step 3: Define Experiment"
@@ -137,17 +137,18 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "12",
+   "id": "13",
    "metadata": {},
    "outputs": [],
    "source": [
+    "# Download data file from repository\n",
     "data_path = ed.download_data(id=22, destination='data')"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "13",
+   "id": "14",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -163,7 +164,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "14",
+   "id": "15",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -173,7 +174,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "15",
+   "id": "16",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -184,7 +185,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "16",
+   "id": "17",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -194,16 +195,16 @@
   },
   {
    "cell_type": "markdown",
-   "id": "17",
+   "id": "18",
    "metadata": {},
    "source": [
-    "## Step 4: Perform Analysis"
+    "## Step 4: Perform Analysis I (ADP iso)"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "18",
+   "id": "19",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -213,7 +214,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "19",
+   "id": "20",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -224,17 +225,17 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "20",
+   "id": "21",
    "metadata": {},
    "outputs": [],
    "source": [
-    "# experiment.show_as_cif()"
+    "project.analysis.current_minimizer = 'lmfit'"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "21",
+   "id": "22",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -246,7 +247,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "22",
+   "id": "23",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -257,17 +258,17 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "23",
+   "id": "24",
    "metadata": {},
    "outputs": [],
    "source": [
-    "# experiment.show_as_cif()"
+    "structure.show_as_cif()"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "24",
+   "id": "25",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -277,7 +278,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "25",
+   "id": "26",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -286,20 +287,104 @@
   },
   {
    "cell_type": "markdown",
-   "id": "26",
+   "id": "27",
    "metadata": {},
    "source": [
-    "## Step 5: Show Project Summary"
+    "## Step 5: Perform Analysis (ADP aniso)"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "27",
+   "id": "28",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "for atom_site in structure.atom_sites:\n",
+    "    atom_site.adp_type = 'Uani'"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "29",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "adp_components = ('adp_11', 'adp_22', 'adp_33', 'adp_12', 'adp_13', 'adp_23')\n",
+    "for atom_site in structure.atom_site_aniso:\n",
+    "    for component in adp_components:\n",
+    "        getattr(atom_site, component).free = True"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "30",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "structure.show_as_cif()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "31",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.analysis.display.free_params()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "32",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.analysis.fit()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "33",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.analysis.display.fit_results()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "34",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.plotter.plot_param_correlations()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "35",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.plotter.plot_meas_vs_calc(expt_name='senju')"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "36",
    "metadata": {},
    "outputs": [],
    "source": [
-    "project.summary.show_report()"
+    "structure.show_as_cif()"
    ]
   }
  ],
diff --git a/docs/docs/tutorials/ed-15.py b/docs/docs/tutorials/ed-15.py
index 617cad88f..0827efae4 100644
--- a/docs/docs/tutorials/ed-15.py
+++ b/docs/docs/tutorials/ed-15.py
@@ -34,12 +34,13 @@
 structure = project.structures['taurine']
 
 # %%
-# structure.show_as_cif()
+structure.show_as_cif()
 
 # %% [markdown]
 # ## Step 3: Define Experiment
 
 # %%
+# Download data file from repository
 data_path = ed.download_data(id=22, destination='data')
 
 # %%
@@ -63,7 +64,7 @@
 experiment.extinction.radius = 100.0
 
 # %% [markdown]
-# ## Step 4: Perform Analysis
+# ## Step 4: Perform Analysis I (ADP iso)
 
 # %%
 project.plotter.plot_meas_vs_calc(expt_name='senju')
@@ -73,7 +74,7 @@
 experiment.extinction.radius.free = True
 
 # %%
-# experiment.show_as_cif()
+project.analysis.current_minimizer = 'lmfit'
 
 # %%
 # Start refinement. All parameters, which have standard uncertainties
@@ -85,7 +86,7 @@
 project.analysis.display.fit_results()
 
 # %%
-# experiment.show_as_cif()
+structure.show_as_cif()
 
 # %%
 project.experiments.show_names()
@@ -94,7 +95,35 @@
 project.plotter.plot_meas_vs_calc(expt_name='senju')
 
 # %% [markdown]
-# ## Step 5: Show Project Summary
+# ## Step 5: Perform Analysis (ADP aniso)
 
 # %%
-project.summary.show_report()
+for atom_site in structure.atom_sites:
+    atom_site.adp_type = 'Uani'
+
+# %%
+adp_components = ('adp_11', 'adp_22', 'adp_33', 'adp_12', 'adp_13', 'adp_23')
+for atom_site in structure.atom_site_aniso:
+    for component in adp_components:
+        getattr(atom_site, component).free = True
+
+# %%
+structure.show_as_cif()
+
+# %%
+project.analysis.display.free_params()
+
+# %%
+project.analysis.fit()
+
+# %%
+project.analysis.display.fit_results()
+
+# %%
+project.plotter.plot_param_correlations()
+
+# %%
+project.plotter.plot_meas_vs_calc(expt_name='senju')
+
+# %%
+structure.show_as_cif()
diff --git a/docs/docs/tutorials/ed-16.ipynb b/docs/docs/tutorials/ed-16.ipynb
index 68dd7243f..cea753497 100644
--- a/docs/docs/tutorials/ed-16.ipynb
+++ b/docs/docs/tutorials/ed-16.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "d0fcc613",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Joint Refinement: Si, Bragg + PDF\n",
@@ -36,7 +36,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Import Library"
@@ -45,7 +45,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -57,7 +57,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Define Structure\n",
@@ -72,7 +72,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -81,7 +81,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "source": [
     "#### Set Space Group"
@@ -90,7 +90,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -100,7 +100,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "7",
+   "id": "8",
    "metadata": {},
    "source": [
     "#### Set Unit Cell"
@@ -109,7 +109,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -118,7 +118,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "source": [
     "#### Set Atom Sites"
@@ -127,7 +127,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "10",
+   "id": "11",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -138,13 +138,13 @@
     "    fract_y=0,\n",
     "    fract_z=0,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.2,\n",
+    "    adp_iso=0.2,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "source": [
     "## Define Experiments\n",
@@ -160,7 +160,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "12",
+   "id": "13",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -169,7 +169,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "13",
+   "id": "14",
    "metadata": {},
    "source": [
     "#### Create Experiment"
@@ -178,7 +178,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "14",
+   "id": "15",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -189,7 +189,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "15",
+   "id": "16",
    "metadata": {},
    "source": [
     "#### Set Instrument"
@@ -198,7 +198,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "16",
+   "id": "17",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -210,7 +210,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "17",
+   "id": "18",
    "metadata": {},
    "source": [
     "#### Set Peak Profile"
@@ -219,23 +219,23 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "18",
+   "id": "19",
    "metadata": {},
    "outputs": [],
    "source": [
-    "bragg_expt.peak_profile_type = 'pseudo-voigt * ikeda-carpenter'\n",
+    "bragg_expt.peak_profile_type = 'jorgensen'\n",
     "bragg_expt.peak.broad_gauss_sigma_0 = 5.0\n",
     "bragg_expt.peak.broad_gauss_sigma_1 = 45.0\n",
     "bragg_expt.peak.broad_gauss_sigma_2 = 1.0\n",
-    "bragg_expt.peak.broad_mix_beta_0 = 0.04221\n",
-    "bragg_expt.peak.broad_mix_beta_1 = 0.00946\n",
-    "bragg_expt.peak.asym_alpha_0 = 0.0\n",
-    "bragg_expt.peak.asym_alpha_1 = 0.5971"
+    "bragg_expt.peak.exp_decay_beta_0 = 0.04221\n",
+    "bragg_expt.peak.exp_decay_beta_1 = 0.00946\n",
+    "bragg_expt.peak.exp_rise_alpha_0 = 0.0\n",
+    "bragg_expt.peak.exp_rise_alpha_1 = 0.5971"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "19",
+   "id": "20",
    "metadata": {},
    "source": [
     "#### Set Background"
@@ -244,7 +244,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "20",
+   "id": "21",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -255,7 +255,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "21",
+   "id": "22",
    "metadata": {},
    "source": [
     "#### Set Linked Phases"
@@ -264,7 +264,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "22",
+   "id": "23",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -273,7 +273,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "23",
+   "id": "24",
    "metadata": {},
    "source": [
     "### Experiment 2: PDF (NOMAD, TOF)\n",
@@ -284,7 +284,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "24",
+   "id": "25",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -293,7 +293,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "25",
+   "id": "26",
    "metadata": {},
    "source": [
     "#### Create Experiment"
@@ -302,7 +302,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "26",
+   "id": "27",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -316,7 +316,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "27",
+   "id": "28",
    "metadata": {},
    "source": [
     "#### Set Peak Profile (PDF Parameters)"
@@ -325,7 +325,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "28",
+   "id": "29",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -339,7 +339,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "29",
+   "id": "30",
    "metadata": {},
    "source": [
     "#### Set Linked Phases"
@@ -348,7 +348,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "30",
+   "id": "31",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -357,7 +357,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "31",
+   "id": "32",
    "metadata": {},
    "source": [
     "## Define Project\n",
@@ -371,7 +371,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "32",
+   "id": "33",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -380,7 +380,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "33",
+   "id": "34",
    "metadata": {},
    "source": [
     "#### Add Structure"
@@ -389,7 +389,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "34",
+   "id": "35",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -398,7 +398,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "35",
+   "id": "36",
    "metadata": {},
    "source": [
     "#### Add Experiments"
@@ -407,7 +407,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "36",
+   "id": "37",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -417,7 +417,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "37",
+   "id": "38",
    "metadata": {},
    "source": [
     "## Perform Analysis\n",
@@ -431,7 +431,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "38",
+   "id": "39",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -442,7 +442,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "39",
+   "id": "40",
    "metadata": {},
    "source": [
     "#### Set Minimizer"
@@ -451,7 +451,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "40",
+   "id": "41",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -460,7 +460,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "41",
+   "id": "42",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated (Before Fit)"
@@ -469,7 +469,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "42",
+   "id": "43",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -479,7 +479,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "43",
+   "id": "44",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -488,7 +488,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "44",
+   "id": "45",
    "metadata": {},
    "source": [
     "#### Set Fitting Parameters\n",
@@ -500,17 +500,17 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "45",
+   "id": "46",
    "metadata": {},
    "outputs": [],
    "source": [
     "structure.cell.length_a.free = True\n",
-    "structure.atom_sites['Si'].b_iso.free = True"
+    "structure.atom_sites['Si'].adp_iso.free = True"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "46",
+   "id": "47",
    "metadata": {},
    "source": [
     "Bragg experiment parameters."
@@ -519,7 +519,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "47",
+   "id": "48",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -534,7 +534,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "48",
+   "id": "49",
    "metadata": {},
    "source": [
     "PDF experiment parameters."
@@ -543,7 +543,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "49",
+   "id": "50",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -556,7 +556,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "50",
+   "id": "51",
    "metadata": {},
    "source": [
     "#### Show Free Parameters"
@@ -565,7 +565,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "51",
+   "id": "52",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -574,7 +574,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "52",
+   "id": "53",
    "metadata": {},
    "source": [
     "#### Run Fitting"
@@ -583,17 +583,18 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "53",
+   "id": "54",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.analysis.fit()\n",
-    "project.analysis.display.fit_results()"
+    "project.analysis.display.fit_results()\n",
+    "project.plotter.plot_param_correlations()"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "54",
+   "id": "55",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated (After Fit)"
@@ -602,7 +603,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "55",
+   "id": "56",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -612,7 +613,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "56",
+   "id": "57",
    "metadata": {},
    "outputs": [],
    "source": [
diff --git a/docs/docs/tutorials/ed-16.py b/docs/docs/tutorials/ed-16.py
index 96c1b3484..d26e149e1 100644
--- a/docs/docs/tutorials/ed-16.py
+++ b/docs/docs/tutorials/ed-16.py
@@ -53,7 +53,7 @@
     fract_y=0,
     fract_z=0,
     wyckoff_letter='a',
-    b_iso=0.2,
+    adp_iso=0.2,
 )
 
 # %% [markdown]
@@ -209,7 +209,7 @@
 
 # %%
 structure.cell.length_a.free = True
-structure.atom_sites['Si'].b_iso.free = True
+structure.atom_sites['Si'].adp_iso.free = True
 
 # %% [markdown]
 # Bragg experiment parameters.
@@ -245,6 +245,7 @@
 # %%
 project.analysis.fit()
 project.analysis.display.fit_results()
+project.plotter.plot_param_correlations()
 
 # %% [markdown]
 # #### Plot Measured vs Calculated (After Fit)
diff --git a/docs/docs/tutorials/ed-17.ipynb b/docs/docs/tutorials/ed-17.ipynb
index 871d18890..484bf20b9 100644
--- a/docs/docs/tutorials/ed-17.ipynb
+++ b/docs/docs/tutorials/ed-17.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "0c20dcfb",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Structure Refinement: Co2SiO4, D20 (T-scan)\n",
@@ -35,7 +35,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Import Library"
@@ -44,7 +44,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -53,7 +53,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Step 1: Define Project\n",
@@ -64,7 +64,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -73,7 +73,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "source": [
     "The project must be saved before running sequential fitting, so that\n",
@@ -83,7 +83,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -92,7 +92,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "7",
+   "id": "8",
    "metadata": {},
    "source": [
     "## Step 2: Define Crystal Structure\n",
@@ -106,7 +106,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -116,7 +116,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "source": [
     "#### Set Space Group"
@@ -125,7 +125,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "10",
+   "id": "11",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -135,7 +135,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "source": [
     "#### Set Unit Cell"
@@ -144,7 +144,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "12",
+   "id": "13",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -155,7 +155,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "13",
+   "id": "14",
    "metadata": {},
    "source": [
     "#### Set Atom Sites"
@@ -164,7 +164,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "14",
+   "id": "15",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -175,7 +175,7 @@
     "    fract_y=0,\n",
     "    fract_z=0,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.3,\n",
+    "    adp_iso=0.3,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='Co2',\n",
@@ -184,7 +184,7 @@
     "    fract_y=0.25,\n",
     "    fract_z=0.985,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=0.3,\n",
+    "    adp_iso=0.3,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='Si',\n",
@@ -193,7 +193,7 @@
     "    fract_y=0.25,\n",
     "    fract_z=0.429,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=0.34,\n",
+    "    adp_iso=0.34,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='O1',\n",
@@ -202,7 +202,7 @@
     "    fract_y=0.25,\n",
     "    fract_z=0.771,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=0.63,\n",
+    "    adp_iso=0.63,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='O2',\n",
@@ -211,7 +211,7 @@
     "    fract_y=0.25,\n",
     "    fract_z=0.217,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=0.59,\n",
+    "    adp_iso=0.59,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='O3',\n",
@@ -220,13 +220,13 @@
     "    fract_y=0.032,\n",
     "    fract_z=0.28,\n",
     "    wyckoff_letter='d',\n",
-    "    b_iso=0.83,\n",
+    "    adp_iso=0.83,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "15",
+   "id": "16",
    "metadata": {},
    "source": [
     "## Step 3: Define Template Experiment\n",
@@ -242,7 +242,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "16",
+   "id": "17",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -251,7 +251,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "17",
+   "id": "18",
    "metadata": {},
    "source": [
     "#### Extract Data Files"
@@ -260,7 +260,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "18",
+   "id": "19",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -270,7 +270,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "19",
+   "id": "20",
    "metadata": {},
    "source": [
     "#### Create Template Experiment from the First File"
@@ -279,7 +279,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "20",
+   "id": "21",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -292,7 +292,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "21",
+   "id": "22",
    "metadata": {},
    "source": [
     "#### Set Instrument"
@@ -301,7 +301,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "22",
+   "id": "23",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -311,7 +311,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "23",
+   "id": "24",
    "metadata": {},
    "source": [
     "#### Set Peak Profile"
@@ -320,7 +320,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "24",
+   "id": "25",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -332,7 +332,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "25",
+   "id": "26",
    "metadata": {},
    "source": [
     "#### Set Excluded Regions"
@@ -341,7 +341,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "26",
+   "id": "27",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -351,7 +351,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "27",
+   "id": "28",
    "metadata": {},
    "source": [
     "#### Set Background"
@@ -360,7 +360,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "28",
+   "id": "29",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -382,7 +382,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "29",
+   "id": "30",
    "metadata": {},
    "source": [
     "#### Set Linked Phases"
@@ -391,7 +391,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "30",
+   "id": "31",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -400,7 +400,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "31",
+   "id": "32",
    "metadata": {},
    "source": [
     "## Step 4: Perform Analysis\n",
@@ -411,7 +411,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "32",
+   "id": "33",
    "metadata": {},
    "source": [
     "#### Set Free Parameters"
@@ -420,7 +420,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "33",
+   "id": "34",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -440,18 +440,18 @@
     "structure.atom_sites['O3'].fract_y.free = True\n",
     "structure.atom_sites['O3'].fract_z.free = True\n",
     "\n",
-    "structure.atom_sites['Co1'].b_iso.free = True\n",
-    "structure.atom_sites['Co2'].b_iso.free = True\n",
-    "structure.atom_sites['Si'].b_iso.free = True\n",
-    "structure.atom_sites['O1'].b_iso.free = True\n",
-    "structure.atom_sites['O2'].b_iso.free = True\n",
-    "structure.atom_sites['O3'].b_iso.free = True"
+    "structure.atom_sites['Co1'].adp_iso.free = True\n",
+    "structure.atom_sites['Co2'].adp_iso.free = True\n",
+    "structure.atom_sites['Si'].adp_iso.free = True\n",
+    "structure.atom_sites['O1'].adp_iso.free = True\n",
+    "structure.atom_sites['O2'].adp_iso.free = True\n",
+    "structure.atom_sites['O3'].adp_iso.free = True"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "34",
+   "id": "35",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -470,7 +470,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "35",
+   "id": "36",
    "metadata": {},
    "source": [
     "#### Set Constraints\n",
@@ -481,23 +481,23 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "36",
+   "id": "37",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.analysis.aliases.create(\n",
     "    label='biso_Co1',\n",
-    "    param=structure.atom_sites['Co1'].b_iso,\n",
+    "    param=structure.atom_sites['Co1'].adp_iso,\n",
     ")\n",
     "project.analysis.aliases.create(\n",
     "    label='biso_Co2',\n",
-    "    param=structure.atom_sites['Co2'].b_iso,\n",
+    "    param=structure.atom_sites['Co2'].adp_iso,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "37",
+   "id": "38",
    "metadata": {},
    "source": [
     "Set constraints."
@@ -506,7 +506,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "38",
+   "id": "39",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -515,7 +515,25 @@
   },
   {
    "cell_type": "markdown",
-   "id": "39",
+   "id": "40",
+   "metadata": {},
+   "source": [
+    "#### Set Minimizer"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "41",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.analysis.current_minimizer = 'bumps (lm)'"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "42",
    "metadata": {},
    "source": [
     "#### Run Single Fitting\n",
@@ -529,7 +547,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "40",
+   "id": "43",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -538,7 +556,25 @@
   },
   {
    "cell_type": "markdown",
-   "id": "41",
+   "id": "44",
+   "metadata": {},
+   "source": [
+    "#### Show parameter correlations"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "45",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.plotter.plot_param_correlations()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "46",
    "metadata": {},
    "source": [
     "#### Compare measured and calculated patterns for the first fit."
@@ -547,7 +583,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "42",
+   "id": "47",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -556,7 +592,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "43",
+   "id": "48",
    "metadata": {},
    "source": [
     "#### Run Sequential Fitting\n",
@@ -568,7 +604,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "44",
+   "id": "49",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -577,7 +613,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "45",
+   "id": "50",
    "metadata": {
     "lines_to_next_cell": 2
    },
@@ -589,7 +625,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "46",
+   "id": "51",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -603,7 +639,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "47",
+   "id": "52",
    "metadata": {},
    "source": [
     "Run the sequential fit over all data files in the scan directory."
@@ -612,7 +648,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "48",
+   "id": "53",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -626,7 +662,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "49",
+   "id": "54",
    "metadata": {},
    "source": [
     "#### Replay a Dataset\n",
@@ -637,7 +673,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "50",
+   "id": "55",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -647,7 +683,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "51",
+   "id": "56",
    "metadata": {},
    "source": [
     "\n",
@@ -657,7 +693,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "52",
+   "id": "57",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -667,7 +703,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "53",
+   "id": "58",
    "metadata": {},
    "source": [
     "#### Plot Parameter Evolution\n",
@@ -678,7 +714,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "54",
+   "id": "59",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -687,7 +723,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "55",
+   "id": "60",
    "metadata": {},
    "source": [
     "Plot unit cell parameters vs. temperature."
@@ -696,7 +732,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "56",
+   "id": "61",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -707,7 +743,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "57",
+   "id": "62",
    "metadata": {},
    "source": [
     "Plot isotropic displacement parameters vs. temperature."
@@ -716,20 +752,20 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "58",
+   "id": "63",
    "metadata": {},
    "outputs": [],
    "source": [
-    "project.plotter.plot_param_series(structure.atom_sites['Co1'].b_iso, versus=temperature)\n",
-    "project.plotter.plot_param_series(structure.atom_sites['Si'].b_iso, versus=temperature)\n",
-    "project.plotter.plot_param_series(structure.atom_sites['O1'].b_iso, versus=temperature)\n",
-    "project.plotter.plot_param_series(structure.atom_sites['O2'].b_iso, versus=temperature)\n",
-    "project.plotter.plot_param_series(structure.atom_sites['O3'].b_iso, versus=temperature)"
+    "project.plotter.plot_param_series(structure.atom_sites['Co1'].adp_iso, versus=temperature)\n",
+    "project.plotter.plot_param_series(structure.atom_sites['Si'].adp_iso, versus=temperature)\n",
+    "project.plotter.plot_param_series(structure.atom_sites['O1'].adp_iso, versus=temperature)\n",
+    "project.plotter.plot_param_series(structure.atom_sites['O2'].adp_iso, versus=temperature)\n",
+    "project.plotter.plot_param_series(structure.atom_sites['O3'].adp_iso, versus=temperature)"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "59",
+   "id": "64",
    "metadata": {},
    "source": [
     "Plot selected fractional coordinates vs. temperature."
@@ -738,7 +774,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "60",
+   "id": "65",
    "metadata": {},
    "outputs": [],
    "source": [
diff --git a/docs/docs/tutorials/ed-17.py b/docs/docs/tutorials/ed-17.py
index 5feb94e83..e0a0299ae 100644
--- a/docs/docs/tutorials/ed-17.py
+++ b/docs/docs/tutorials/ed-17.py
@@ -66,7 +66,7 @@
     fract_y=0,
     fract_z=0,
     wyckoff_letter='a',
-    b_iso=0.3,
+    adp_iso=0.3,
 )
 structure.atom_sites.create(
     label='Co2',
@@ -75,7 +75,7 @@
     fract_y=0.25,
     fract_z=0.985,
     wyckoff_letter='c',
-    b_iso=0.3,
+    adp_iso=0.3,
 )
 structure.atom_sites.create(
     label='Si',
@@ -84,7 +84,7 @@
     fract_y=0.25,
     fract_z=0.429,
     wyckoff_letter='c',
-    b_iso=0.34,
+    adp_iso=0.34,
 )
 structure.atom_sites.create(
     label='O1',
@@ -93,7 +93,7 @@
     fract_y=0.25,
     fract_z=0.771,
     wyckoff_letter='c',
-    b_iso=0.63,
+    adp_iso=0.63,
 )
 structure.atom_sites.create(
     label='O2',
@@ -102,7 +102,7 @@
     fract_y=0.25,
     fract_z=0.217,
     wyckoff_letter='c',
-    b_iso=0.59,
+    adp_iso=0.59,
 )
 structure.atom_sites.create(
     label='O3',
@@ -111,7 +111,7 @@
     fract_y=0.032,
     fract_z=0.28,
     wyckoff_letter='d',
-    b_iso=0.83,
+    adp_iso=0.83,
 )
 
 # %% [markdown]
@@ -218,12 +218,12 @@
 structure.atom_sites['O3'].fract_y.free = True
 structure.atom_sites['O3'].fract_z.free = True
 
-structure.atom_sites['Co1'].b_iso.free = True
-structure.atom_sites['Co2'].b_iso.free = True
-structure.atom_sites['Si'].b_iso.free = True
-structure.atom_sites['O1'].b_iso.free = True
-structure.atom_sites['O2'].b_iso.free = True
-structure.atom_sites['O3'].b_iso.free = True
+structure.atom_sites['Co1'].adp_iso.free = True
+structure.atom_sites['Co2'].adp_iso.free = True
+structure.atom_sites['Si'].adp_iso.free = True
+structure.atom_sites['O1'].adp_iso.free = True
+structure.atom_sites['O2'].adp_iso.free = True
+structure.atom_sites['O3'].adp_iso.free = True
 
 # %%
 expt.linked_phases['cosio'].scale.free = True
@@ -246,11 +246,11 @@
 # %%
 project.analysis.aliases.create(
     label='biso_Co1',
-    param=structure.atom_sites['Co1'].b_iso,
+    param=structure.atom_sites['Co1'].adp_iso,
 )
 project.analysis.aliases.create(
     label='biso_Co2',
-    param=structure.atom_sites['Co2'].b_iso,
+    param=structure.atom_sites['Co2'].adp_iso,
 )
 
 # %% [markdown]
@@ -276,6 +276,12 @@
 # %%
 project.analysis.fit()
 
+# %% [markdown]
+# #### Show parameter correlations
+
+# %%
+project.plotter.plot_param_correlations()
+
 # %% [markdown]
 # #### Compare measured and calculated patterns for the first fit.
 
@@ -353,11 +359,11 @@ def extract_diffrn(file_path):
 # Plot isotropic displacement parameters vs. temperature.
 
 # %%
-project.plotter.plot_param_series(structure.atom_sites['Co1'].b_iso, versus=temperature)
-project.plotter.plot_param_series(structure.atom_sites['Si'].b_iso, versus=temperature)
-project.plotter.plot_param_series(structure.atom_sites['O1'].b_iso, versus=temperature)
-project.plotter.plot_param_series(structure.atom_sites['O2'].b_iso, versus=temperature)
-project.plotter.plot_param_series(structure.atom_sites['O3'].b_iso, versus=temperature)
+project.plotter.plot_param_series(structure.atom_sites['Co1'].adp_iso, versus=temperature)
+project.plotter.plot_param_series(structure.atom_sites['Si'].adp_iso, versus=temperature)
+project.plotter.plot_param_series(structure.atom_sites['O1'].adp_iso, versus=temperature)
+project.plotter.plot_param_series(structure.atom_sites['O2'].adp_iso, versus=temperature)
+project.plotter.plot_param_series(structure.atom_sites['O3'].adp_iso, versus=temperature)
 
 # %% [markdown]
 # Plot selected fractional coordinates vs. temperature.
diff --git a/docs/docs/tutorials/ed-18.ipynb b/docs/docs/tutorials/ed-18.ipynb
index 655a0b808..2cc2b7fde 100644
--- a/docs/docs/tutorials/ed-18.ipynb
+++ b/docs/docs/tutorials/ed-18.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "f9d269b5",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Load Project and Fit: LBCO, HRPT\n",
@@ -39,7 +39,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Import Modules"
@@ -48,7 +48,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -59,7 +59,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Download Project Archive"
@@ -68,16 +68,16 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "outputs": [],
    "source": [
-    "zip_path = download_data(id=28, destination='data')"
+    "zip_path = download_data(id=30, destination='data')"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "source": [
     "## Extract Project"
@@ -86,7 +86,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -95,7 +95,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "7",
+   "id": "8",
    "metadata": {},
    "source": [
     "## Load Project"
@@ -104,7 +104,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -113,7 +113,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "source": [
     "## Perform Analysis"
@@ -122,7 +122,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "10",
+   "id": "11",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -131,7 +131,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "source": [
     "## Show Results"
@@ -140,7 +140,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "12",
+   "id": "13",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -149,7 +149,25 @@
   },
   {
    "cell_type": "markdown",
-   "id": "13",
+   "id": "14",
+   "metadata": {},
+   "source": [
+    "#### Show parameter correlations"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "15",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.plotter.plot_param_correlations()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "16",
    "metadata": {},
    "source": [
     "## Plot Meas vs Calc"
@@ -158,7 +176,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "14",
+   "id": "17",
    "metadata": {},
    "outputs": [],
    "source": [
diff --git a/docs/docs/tutorials/ed-18.py b/docs/docs/tutorials/ed-18.py
index fbfd39e58..07310726f 100644
--- a/docs/docs/tutorials/ed-18.py
+++ b/docs/docs/tutorials/ed-18.py
@@ -23,7 +23,7 @@
 # ## Download Project Archive
 
 # %%
-zip_path = download_data(id=28, destination='data')
+zip_path = download_data(id=30, destination='data')
 
 # %% [markdown]
 # ## Extract Project
@@ -49,6 +49,12 @@
 # %%
 project.analysis.display.fit_results()
 
+# %% [markdown]
+# #### Show parameter correlations
+
+# %%
+project.plotter.plot_param_correlations()
+
 # %% [markdown]
 # ## Plot Meas vs Calc
 
diff --git a/docs/docs/tutorials/ed-2.ipynb b/docs/docs/tutorials/ed-2.ipynb
index 3b359bcb1..ab01aee03 100644
--- a/docs/docs/tutorials/ed-2.ipynb
+++ b/docs/docs/tutorials/ed-2.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "9e18bf0f",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Structure Refinement: LBCO, HRPT\n",
@@ -48,7 +48,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Import Library"
@@ -57,7 +57,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -66,7 +66,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Step 1: Define Project"
@@ -75,7 +75,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -84,7 +84,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "source": [
     "## Step 2: Define Structure"
@@ -93,7 +93,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -103,7 +103,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "7",
+   "id": "8",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -113,7 +113,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -124,7 +124,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -134,7 +134,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "10",
+   "id": "11",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -145,7 +145,7 @@
     "    fract_y=0,\n",
     "    fract_z=0,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     "    occupancy=0.5,\n",
     ")\n",
     "structure.atom_sites.create(\n",
@@ -155,7 +155,7 @@
     "    fract_y=0,\n",
     "    fract_z=0,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     "    occupancy=0.5,\n",
     ")\n",
     "structure.atom_sites.create(\n",
@@ -165,7 +165,7 @@
     "    fract_y=0.5,\n",
     "    fract_z=0.5,\n",
     "    wyckoff_letter='b',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='O',\n",
@@ -174,13 +174,13 @@
     "    fract_y=0.5,\n",
     "    fract_z=0.5,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "source": [
     "## Step 3: Define Experiment"
@@ -189,7 +189,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "12",
+   "id": "13",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -199,7 +199,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "13",
+   "id": "14",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -215,7 +215,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "14",
+   "id": "15",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -225,7 +225,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "15",
+   "id": "16",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -236,7 +236,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "16",
+   "id": "17",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -249,7 +249,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "17",
+   "id": "18",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -263,7 +263,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "18",
+   "id": "19",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -274,7 +274,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "19",
+   "id": "20",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -283,34 +283,32 @@
   },
   {
    "cell_type": "markdown",
-   "id": "20",
+   "id": "21",
    "metadata": {},
    "source": [
-    "## Step 4: Perform Analysis"
+    "## Step 4: Perform Analysis (no constraints)"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "21",
+   "id": "22",
    "metadata": {},
    "outputs": [],
    "source": [
     "structure.cell.length_a.free = True\n",
     "\n",
-    "structure.atom_sites['La'].b_iso.free = True\n",
-    "structure.atom_sites['Ba'].b_iso.free = True\n",
-    "structure.atom_sites['Co'].b_iso.free = True\n",
-    "structure.atom_sites['O'].b_iso.free = True"
+    "structure.atom_sites['La'].adp_iso.free = True\n",
+    "structure.atom_sites['Ba'].adp_iso.free = True\n",
+    "structure.atom_sites['Co'].adp_iso.free = True\n",
+    "structure.atom_sites['O'].adp_iso.free = True"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "22",
-   "metadata": {
-    "lines_to_next_cell": 2
-   },
+   "id": "23",
+   "metadata": {},
    "outputs": [],
    "source": [
     "experiment.instrument.calib_twotheta_offset.free = True\n",
@@ -332,18 +330,110 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "23",
+   "id": "24",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.analysis.fit()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "25",
    "metadata": {},
    "outputs": [],
    "source": [
-    "project.analysis.fit()\n",
     "project.analysis.display.fit_results()"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "24",
+   "id": "26",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.plotter.plot_param_correlations()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "27",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.plotter.plot_meas_vs_calc(expt_name='hrpt', show_residual=True)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "28",
+   "metadata": {},
+   "source": [
+    "## Step 5: Perform Analysis (with constraints)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "29",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# As can be seen from the parameter-correlation plot, the isotropic\n",
+    "# displacement parameters of La and Ba are highly correlated. Because\n",
+    "# La and Ba share the same mixed-occupancy site, their contributions to\n",
+    "# the neutron diffraction pattern are difficult to separate, especially\n",
+    "# since their coherent scattering lengths are not very different.\n",
+    "# Therefore, it is necessary to constrain them to be equal. First we\n",
+    "# define aliases and then use them to create a constraint.\n",
+    "project.analysis.aliases.create(\n",
+    "    label='biso_La',\n",
+    "    param=project.structures['lbco'].atom_sites['La'].adp_iso,\n",
+    ")\n",
+    "project.analysis.aliases.create(\n",
+    "    label='biso_Ba',\n",
+    "    param=project.structures['lbco'].atom_sites['Ba'].adp_iso,\n",
+    ")\n",
+    "project.analysis.constraints.create(expression='biso_Ba = biso_La')"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "30",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.analysis.fit()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "31",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.analysis.display.fit_results()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "32",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.plotter.plot_param_correlations()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "33",
    "metadata": {},
    "outputs": [],
    "source": [
diff --git a/docs/docs/tutorials/ed-2.py b/docs/docs/tutorials/ed-2.py
index 609f54db9..b5d1d8e6f 100644
--- a/docs/docs/tutorials/ed-2.py
+++ b/docs/docs/tutorials/ed-2.py
@@ -56,7 +56,7 @@
     fract_y=0,
     fract_z=0,
     wyckoff_letter='a',
-    b_iso=0.5,
+    adp_iso=0.5,
     occupancy=0.5,
 )
 structure.atom_sites.create(
@@ -66,7 +66,7 @@
     fract_y=0,
     fract_z=0,
     wyckoff_letter='a',
-    b_iso=0.5,
+    adp_iso=0.5,
     occupancy=0.5,
 )
 structure.atom_sites.create(
@@ -76,7 +76,7 @@
     fract_y=0.5,
     fract_z=0.5,
     wyckoff_letter='b',
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 structure.atom_sites.create(
     label='O',
@@ -85,7 +85,7 @@
     fract_y=0.5,
     fract_z=0.5,
     wyckoff_letter='c',
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 
 # %% [markdown]
@@ -131,15 +131,15 @@
 experiment.linked_phases.create(id='lbco', scale=10.0)
 
 # %% [markdown]
-# ## Step 4: Perform Analysis
+# ## Step 4: Perform Analysis (no constraints)
 
 # %%
 structure.cell.length_a.free = True
 
-structure.atom_sites['La'].b_iso.free = True
-structure.atom_sites['Ba'].b_iso.free = True
-structure.atom_sites['Co'].b_iso.free = True
-structure.atom_sites['O'].b_iso.free = True
+structure.atom_sites['La'].adp_iso.free = True
+structure.atom_sites['Ba'].adp_iso.free = True
+structure.atom_sites['Co'].adp_iso.free = True
+structure.atom_sites['O'].adp_iso.free = True
 
 # %%
 experiment.instrument.calib_twotheta_offset.free = True
@@ -157,10 +157,47 @@
 
 experiment.linked_phases['lbco'].scale.free = True
 
+# %%
+project.analysis.fit()
+
+# %%
+project.analysis.display.fit_results()
+
+# %%
+project.plotter.plot_param_correlations()
+
+# %%
+project.plotter.plot_meas_vs_calc(expt_name='hrpt', show_residual=True)
+
+# %% [markdown]
+# ## Step 5: Perform Analysis (with constraints)
+
+# %%
+# As can be seen from the parameter-correlation plot, the isotropic
+# displacement parameters of La and Ba are highly correlated. Because
+# La and Ba share the same mixed-occupancy site, their contributions to
+# the neutron diffraction pattern are difficult to separate, especially
+# since their coherent scattering lengths are not very different.
+# Therefore, it is necessary to constrain them to be equal. First we
+# define aliases and then use them to create a constraint.
+project.analysis.aliases.create(
+    label='biso_La',
+    param=project.structures['lbco'].atom_sites['La'].adp_iso,
+)
+project.analysis.aliases.create(
+    label='biso_Ba',
+    param=project.structures['lbco'].atom_sites['Ba'].adp_iso,
+)
+project.analysis.constraints.create(expression='biso_Ba = biso_La')
 
 # %%
 project.analysis.fit()
+
+# %%
 project.analysis.display.fit_results()
 
+# %%
+project.plotter.plot_param_correlations()
+
 # %%
 project.plotter.plot_meas_vs_calc(expt_name='hrpt', show_residual=True)
diff --git a/docs/docs/tutorials/ed-3.ipynb b/docs/docs/tutorials/ed-3.ipynb
index 7b4099b1d..8bc929ff8 100644
--- a/docs/docs/tutorials/ed-3.ipynb
+++ b/docs/docs/tutorials/ed-3.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "3e463ed0",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Structure Refinement: LBCO, HRPT\n",
@@ -46,7 +46,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Import Library"
@@ -55,7 +55,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -64,7 +64,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Step 1: Create a Project\n",
@@ -74,7 +74,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "source": [
     "#### Create Project"
@@ -83,7 +83,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -92,7 +92,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "source": [
     "#### Set Project Metadata"
@@ -101,7 +101,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "7",
+   "id": "8",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -114,7 +114,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "source": [
     "#### Show Project Metadata as CIF"
@@ -123,7 +123,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -132,7 +132,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "10",
+   "id": "11",
    "metadata": {},
    "source": [
     "#### Save Project\n",
@@ -145,7 +145,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -154,7 +154,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "12",
+   "id": "13",
    "metadata": {},
    "source": [
     "#### Set Up Data Plotter"
@@ -162,7 +162,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "13",
+   "id": "14",
    "metadata": {},
    "source": [
     "Show supported plotting engines."
@@ -171,7 +171,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "14",
+   "id": "15",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -180,7 +180,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "15",
+   "id": "16",
    "metadata": {},
    "source": [
     "Show current plotting configuration."
@@ -189,7 +189,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "16",
+   "id": "17",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -198,28 +198,8 @@
   },
   {
    "cell_type": "markdown",
-   "id": "17",
-   "metadata": {},
-   "source": [
-    "Set plotting engine."
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
    "id": "18",
    "metadata": {},
-   "outputs": [],
-   "source": [
-    "# Keep the auto-selected engine. Alternatively, you can uncomment the\n",
-    "# line below to explicitly set the engine to the required one.\n",
-    "# project.plotter.engine = 'plotly'"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "id": "19",
-   "metadata": {},
    "source": [
     "## Step 2: Define Structure\n",
     "\n",
@@ -229,7 +209,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "20",
+   "id": "19",
    "metadata": {},
    "source": [
     "#### Add Structure"
@@ -238,7 +218,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "21",
+   "id": "20",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -247,7 +227,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "22",
+   "id": "21",
    "metadata": {},
    "source": [
     "#### Show Defined Structures\n",
@@ -261,7 +241,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "23",
+   "id": "22",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -270,7 +250,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "24",
+   "id": "23",
    "metadata": {},
    "source": [
     "#### Set Space Group\n",
@@ -281,7 +261,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "25",
+   "id": "24",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -291,7 +271,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "26",
+   "id": "25",
    "metadata": {},
    "source": [
     "#### Set Unit Cell\n",
@@ -302,7 +282,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "27",
+   "id": "26",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -311,7 +291,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "28",
+   "id": "27",
    "metadata": {},
    "source": [
     "#### Set Atom Sites\n",
@@ -322,7 +302,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "29",
+   "id": "28",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -333,7 +313,7 @@
     "    fract_y=0,\n",
     "    fract_z=0,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     "    occupancy=0.5,\n",
     ")\n",
     "project.structures['lbco'].atom_sites.create(\n",
@@ -343,7 +323,7 @@
     "    fract_y=0,\n",
     "    fract_z=0,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     "    occupancy=0.5,\n",
     ")\n",
     "project.structures['lbco'].atom_sites.create(\n",
@@ -353,7 +333,7 @@
     "    fract_y=0.5,\n",
     "    fract_z=0.5,\n",
     "    wyckoff_letter='b',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")\n",
     "project.structures['lbco'].atom_sites.create(\n",
     "    label='O',\n",
@@ -362,13 +342,13 @@
     "    fract_y=0.5,\n",
     "    fract_z=0.5,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "30",
+   "id": "29",
    "metadata": {},
    "source": [
     "#### Show Structure as CIF"
@@ -377,7 +357,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "31",
+   "id": "30",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -386,7 +366,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "32",
+   "id": "31",
    "metadata": {},
    "source": [
     "#### Show Structure Structure"
@@ -395,7 +375,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "33",
+   "id": "32",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -404,7 +384,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "34",
+   "id": "33",
    "metadata": {},
    "source": [
     "#### Save Project State\n",
@@ -417,7 +397,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "35",
+   "id": "34",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -426,7 +406,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "36",
+   "id": "35",
    "metadata": {},
    "source": [
     "## Step 3: Define Experiment\n",
@@ -437,7 +417,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "37",
+   "id": "36",
    "metadata": {},
    "source": [
     "#### Download Measured Data\n",
@@ -448,7 +428,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "38",
+   "id": "37",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -457,7 +437,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "39",
+   "id": "38",
    "metadata": {},
    "source": [
     "#### Add Diffraction Experiment"
@@ -466,7 +446,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "40",
+   "id": "39",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -481,7 +461,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "41",
+   "id": "40",
    "metadata": {},
    "source": [
     "#### Show Defined Experiments"
@@ -490,7 +470,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "42",
+   "id": "41",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -499,7 +479,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "43",
+   "id": "42",
    "metadata": {},
    "source": [
     "#### Show Measured Data"
@@ -508,7 +488,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "44",
+   "id": "43",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -517,7 +497,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "45",
+   "id": "44",
    "metadata": {},
    "source": [
     "#### Set Instrument\n",
@@ -528,7 +508,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "46",
+   "id": "45",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -538,7 +518,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "47",
+   "id": "46",
    "metadata": {},
    "source": [
     "#### Set Peak Profile\n",
@@ -549,7 +529,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "48",
+   "id": "47",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -558,7 +538,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "49",
+   "id": "48",
    "metadata": {},
    "source": [
     "Show the current peak profile type."
@@ -567,7 +547,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "50",
+   "id": "49",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -576,7 +556,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "51",
+   "id": "50",
    "metadata": {},
    "source": [
     "Select the desired peak profile type."
@@ -585,7 +565,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "52",
+   "id": "51",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -594,7 +574,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "53",
+   "id": "52",
    "metadata": {},
    "source": [
     "Modify default peak profile parameters."
@@ -603,7 +583,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "54",
+   "id": "53",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -616,7 +596,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "55",
+   "id": "54",
    "metadata": {},
    "source": [
     "#### Set Background"
@@ -624,7 +604,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "56",
+   "id": "55",
    "metadata": {},
    "source": [
     "Show supported background types."
@@ -633,7 +613,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "57",
+   "id": "56",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -642,7 +622,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "58",
+   "id": "57",
    "metadata": {},
    "source": [
     "Show current background type."
@@ -651,7 +631,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "59",
+   "id": "58",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -660,7 +640,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "60",
+   "id": "59",
    "metadata": {},
    "source": [
     "Select the desired background type."
@@ -669,7 +649,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "61",
+   "id": "60",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -678,7 +658,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "62",
+   "id": "61",
    "metadata": {},
    "source": [
     "Add background points."
@@ -687,7 +667,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "63",
+   "id": "62",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -700,7 +680,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "64",
+   "id": "63",
    "metadata": {},
    "source": [
     "Show current background points."
@@ -709,7 +689,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "65",
+   "id": "64",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -718,7 +698,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "66",
+   "id": "65",
    "metadata": {},
    "source": [
     "#### Set Linked Phases\n",
@@ -729,7 +709,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "67",
+   "id": "66",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -738,7 +718,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "68",
+   "id": "67",
    "metadata": {},
    "source": [
     "#### Show Experiment as CIF"
@@ -747,7 +727,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "69",
+   "id": "68",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -756,7 +736,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "70",
+   "id": "69",
    "metadata": {},
    "source": [
     "#### Save Project State"
@@ -765,7 +745,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "71",
+   "id": "70",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -774,7 +754,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "72",
+   "id": "71",
    "metadata": {},
    "source": [
     "## Step 4: Perform Analysis\n",
@@ -790,7 +770,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "73",
+   "id": "72",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -799,7 +779,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "74",
+   "id": "73",
    "metadata": {},
    "source": [
     "Show current calculation engine for this experiment."
@@ -808,7 +788,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "75",
+   "id": "74",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -817,7 +797,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "76",
+   "id": "75",
    "metadata": {},
    "source": [
     "Select the desired calculation engine."
@@ -826,7 +806,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "77",
+   "id": "76",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -835,7 +815,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "78",
+   "id": "77",
    "metadata": {},
    "source": [
     "#### Show Calculated Data"
@@ -844,7 +824,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "79",
+   "id": "78",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -853,7 +833,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "80",
+   "id": "79",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -862,7 +842,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "81",
+   "id": "80",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -872,7 +852,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "82",
+   "id": "81",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -881,7 +861,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "83",
+   "id": "82",
    "metadata": {},
    "source": [
     "#### Show Parameters\n",
@@ -892,7 +872,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "84",
+   "id": "83",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -901,7 +881,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "85",
+   "id": "84",
    "metadata": {},
    "source": [
     "Show all fittable parameters."
@@ -910,7 +890,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "86",
+   "id": "85",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -919,7 +899,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "87",
+   "id": "86",
    "metadata": {},
    "source": [
     "Show only free parameters."
@@ -928,7 +908,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "88",
+   "id": "87",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -937,7 +917,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "89",
+   "id": "88",
    "metadata": {},
    "source": [
     "Show how to access parameters in the code."
@@ -946,7 +926,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "90",
+   "id": "89",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -955,7 +935,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "91",
+   "id": "90",
    "metadata": {},
    "source": [
     "#### Set Fit Mode\n",
@@ -966,7 +946,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "92",
+   "id": "91",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -975,7 +955,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "93",
+   "id": "92",
    "metadata": {},
    "source": [
     "Show current fit mode."
@@ -984,7 +964,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "94",
+   "id": "93",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -993,7 +973,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "95",
+   "id": "94",
    "metadata": {},
    "source": [
     "Select desired fit mode."
@@ -1002,7 +982,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "96",
+   "id": "95",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1011,7 +991,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "97",
+   "id": "96",
    "metadata": {},
    "source": [
     "#### Set Minimizer\n",
@@ -1022,7 +1002,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "98",
+   "id": "97",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1031,7 +1011,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "99",
+   "id": "98",
    "metadata": {},
    "source": [
     "Show current fitting engine."
@@ -1040,7 +1020,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "100",
+   "id": "99",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1049,7 +1029,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "101",
+   "id": "100",
    "metadata": {},
    "source": [
     "Select desired fitting engine."
@@ -1058,7 +1038,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "102",
+   "id": "101",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1067,7 +1047,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "103",
+   "id": "102",
    "metadata": {},
    "source": [
     "### Perform Fit 1/5\n",
@@ -1078,7 +1058,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "104",
+   "id": "103",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1087,7 +1067,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "105",
+   "id": "104",
    "metadata": {},
    "source": [
     "Set experiment parameters to be refined."
@@ -1096,7 +1076,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "106",
+   "id": "105",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1111,7 +1091,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "107",
+   "id": "106",
    "metadata": {},
    "source": [
     "Show free parameters after selection."
@@ -1120,7 +1100,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "108",
+   "id": "107",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1129,7 +1109,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "109",
+   "id": "108",
    "metadata": {},
    "source": [
     "#### Run Fitting"
@@ -1138,7 +1118,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "110",
+   "id": "109",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1148,7 +1128,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "111",
+   "id": "110",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -1157,7 +1137,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "112",
+   "id": "111",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1167,7 +1147,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "113",
+   "id": "112",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1176,7 +1156,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "114",
+   "id": "113",
    "metadata": {},
    "source": [
     "#### Save Project State"
@@ -1185,7 +1165,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "115",
+   "id": "114",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1194,7 +1174,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "116",
+   "id": "115",
    "metadata": {},
    "source": [
     "### Perform Fit 2/5\n",
@@ -1205,7 +1185,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "117",
+   "id": "116",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1217,7 +1197,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "118",
+   "id": "117",
    "metadata": {},
    "source": [
     "Show free parameters after selection."
@@ -1226,7 +1206,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "119",
+   "id": "118",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1235,7 +1215,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "120",
+   "id": "119",
    "metadata": {},
    "source": [
     "#### Run Fitting"
@@ -1244,7 +1224,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "121",
+   "id": "120",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1254,7 +1234,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "122",
+   "id": "121",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -1263,7 +1243,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "123",
+   "id": "122",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1273,7 +1253,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "124",
+   "id": "123",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1282,7 +1262,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "125",
+   "id": "124",
    "metadata": {},
    "source": [
     "#### Save Project State"
@@ -1291,7 +1271,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "126",
+   "id": "125",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1300,7 +1280,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "127",
+   "id": "126",
    "metadata": {},
    "source": [
     "### Perform Fit 3/5\n",
@@ -1311,19 +1291,19 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "128",
+   "id": "127",
    "metadata": {},
    "outputs": [],
    "source": [
-    "project.structures['lbco'].atom_sites['La'].b_iso.free = True\n",
-    "project.structures['lbco'].atom_sites['Ba'].b_iso.free = True\n",
-    "project.structures['lbco'].atom_sites['Co'].b_iso.free = True\n",
-    "project.structures['lbco'].atom_sites['O'].b_iso.free = True"
+    "project.structures['lbco'].atom_sites['La'].adp_iso.free = True\n",
+    "project.structures['lbco'].atom_sites['Ba'].adp_iso.free = True\n",
+    "project.structures['lbco'].atom_sites['Co'].adp_iso.free = True\n",
+    "project.structures['lbco'].atom_sites['O'].adp_iso.free = True"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "129",
+   "id": "128",
    "metadata": {},
    "source": [
     "Show free parameters after selection."
@@ -1332,7 +1312,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "130",
+   "id": "129",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1341,7 +1321,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "131",
+   "id": "130",
    "metadata": {},
    "source": [
     "#### Run Fitting"
@@ -1350,7 +1330,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "132",
+   "id": "131",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1360,7 +1340,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "133",
+   "id": "132",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -1369,7 +1349,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "134",
+   "id": "133",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1379,7 +1359,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "135",
+   "id": "134",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1388,7 +1368,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "136",
+   "id": "135",
    "metadata": {},
    "source": [
     "#### Save Project State"
@@ -1397,7 +1377,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "137",
+   "id": "136",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1406,7 +1386,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "138",
+   "id": "137",
    "metadata": {},
    "source": [
     "### Perform Fit 4/5\n",
@@ -1419,23 +1399,23 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "139",
+   "id": "138",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.analysis.aliases.create(\n",
     "    label='biso_La',\n",
-    "    param=project.structures['lbco'].atom_sites['La'].b_iso,\n",
+    "    param=project.structures['lbco'].atom_sites['La'].adp_iso,\n",
     ")\n",
     "project.analysis.aliases.create(\n",
     "    label='biso_Ba',\n",
-    "    param=project.structures['lbco'].atom_sites['Ba'].b_iso,\n",
+    "    param=project.structures['lbco'].atom_sites['Ba'].adp_iso,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "140",
+   "id": "139",
    "metadata": {},
    "source": [
     "Set constraints."
@@ -1444,7 +1424,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "141",
+   "id": "140",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1453,7 +1433,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "142",
+   "id": "141",
    "metadata": {},
    "source": [
     "Show defined constraints."
@@ -1462,7 +1442,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "143",
+   "id": "142",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1471,7 +1451,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "144",
+   "id": "143",
    "metadata": {},
    "source": [
     "Show free parameters."
@@ -1480,7 +1460,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "145",
+   "id": "144",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1489,7 +1469,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "146",
+   "id": "145",
    "metadata": {},
    "source": [
     "#### Run Fitting"
@@ -1498,7 +1478,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "147",
+   "id": "146",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1508,7 +1488,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "148",
+   "id": "147",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -1517,7 +1497,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "149",
+   "id": "148",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1527,7 +1507,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "150",
+   "id": "149",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1536,7 +1516,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "151",
+   "id": "150",
    "metadata": {},
    "source": [
     "#### Save Project State"
@@ -1545,7 +1525,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "152",
+   "id": "151",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1554,7 +1534,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "153",
+   "id": "152",
    "metadata": {},
    "source": [
     "### Perform Fit 5/5\n",
@@ -1567,7 +1547,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "154",
+   "id": "153",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1583,7 +1563,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "155",
+   "id": "154",
    "metadata": {},
    "source": [
     "Set more constraints."
@@ -1592,7 +1572,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "156",
+   "id": "155",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1603,7 +1583,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "157",
+   "id": "156",
    "metadata": {},
    "source": [
     "Show defined constraints."
@@ -1612,7 +1592,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "158",
+   "id": "157",
    "metadata": {
     "lines_to_next_cell": 2
    },
@@ -1623,7 +1603,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "159",
+   "id": "158",
    "metadata": {},
    "source": [
     "Set structure parameters to be refined."
@@ -1632,7 +1612,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "160",
+   "id": "159",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1641,7 +1621,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "161",
+   "id": "160",
    "metadata": {},
    "source": [
     "Show free parameters after selection."
@@ -1650,7 +1630,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "162",
+   "id": "161",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1659,7 +1639,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "163",
+   "id": "162",
    "metadata": {},
    "source": [
     "#### Run Fitting"
@@ -1668,17 +1648,18 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "164",
+   "id": "163",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.analysis.fit()\n",
-    "project.analysis.display.fit_results()"
+    "project.analysis.display.fit_results()\n",
+    "project.plotter.plot_param_correlations()"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "165",
+   "id": "164",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -1687,7 +1668,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "166",
+   "id": "165",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1697,7 +1678,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "167",
+   "id": "166",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1706,7 +1687,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "168",
+   "id": "167",
    "metadata": {},
    "source": [
     "#### Save Project State"
@@ -1715,7 +1696,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "169",
+   "id": "168",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1724,7 +1705,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "170",
+   "id": "169",
    "metadata": {},
    "source": [
     "## Step 5: Summary\n",
@@ -1734,7 +1715,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "171",
+   "id": "170",
    "metadata": {},
    "source": [
     "#### Show Project Summary"
@@ -1743,20 +1724,12 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "172",
+   "id": "171",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.summary.show_report()"
    ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "173",
-   "metadata": {},
-   "outputs": [],
-   "source": []
   }
  ],
  "metadata": {
diff --git a/docs/docs/tutorials/ed-3.py b/docs/docs/tutorials/ed-3.py
index d6ad73598..9f9219ac1 100644
--- a/docs/docs/tutorials/ed-3.py
+++ b/docs/docs/tutorials/ed-3.py
@@ -129,7 +129,7 @@
     fract_y=0,
     fract_z=0,
     wyckoff_letter='a',
-    b_iso=0.5,
+    adp_iso=0.5,
     occupancy=0.5,
 )
 project.structures['lbco'].atom_sites.create(
@@ -139,7 +139,7 @@
     fract_y=0,
     fract_z=0,
     wyckoff_letter='a',
-    b_iso=0.5,
+    adp_iso=0.5,
     occupancy=0.5,
 )
 project.structures['lbco'].atom_sites.create(
@@ -149,7 +149,7 @@
     fract_y=0.5,
     fract_z=0.5,
     wyckoff_letter='b',
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 project.structures['lbco'].atom_sites.create(
     label='O',
@@ -158,7 +158,7 @@
     fract_y=0.5,
     fract_z=0.5,
     wyckoff_letter='c',
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 
 # %% [markdown]
@@ -516,10 +516,10 @@
 # Set more parameters to be refined.
 
 # %%
-project.structures['lbco'].atom_sites['La'].b_iso.free = True
-project.structures['lbco'].atom_sites['Ba'].b_iso.free = True
-project.structures['lbco'].atom_sites['Co'].b_iso.free = True
-project.structures['lbco'].atom_sites['O'].b_iso.free = True
+project.structures['lbco'].atom_sites['La'].adp_iso.free = True
+project.structures['lbco'].atom_sites['Ba'].adp_iso.free = True
+project.structures['lbco'].atom_sites['Co'].adp_iso.free = True
+project.structures['lbco'].atom_sites['O'].adp_iso.free = True
 
 # %% [markdown]
 # Show free parameters after selection.
@@ -559,11 +559,11 @@
 # %%
 project.analysis.aliases.create(
     label='biso_La',
-    param=project.structures['lbco'].atom_sites['La'].b_iso,
+    param=project.structures['lbco'].atom_sites['La'].adp_iso,
 )
 project.analysis.aliases.create(
     label='biso_Ba',
-    param=project.structures['lbco'].atom_sites['Ba'].b_iso,
+    param=project.structures['lbco'].atom_sites['Ba'].adp_iso,
 )
 
 # %% [markdown]
@@ -656,6 +656,7 @@
 # %%
 project.analysis.fit()
 project.analysis.display.fit_results()
+project.plotter.plot_param_correlations()
 
 # %% [markdown]
 # #### Plot Measured vs Calculated
@@ -682,5 +683,3 @@
 
 # %%
 project.summary.show_report()
-
-# %%
diff --git a/docs/docs/tutorials/ed-4.ipynb b/docs/docs/tutorials/ed-4.ipynb
index 82ecbcc2f..957c90053 100644
--- a/docs/docs/tutorials/ed-4.ipynb
+++ b/docs/docs/tutorials/ed-4.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "d969fc08",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Structure Refinement: PbSO4, NPD + XRD\n",
@@ -39,7 +39,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Import Library"
@@ -48,7 +48,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -60,7 +60,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Define Structure\n",
@@ -74,7 +74,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -83,7 +83,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "source": [
     "#### Set Space Group"
@@ -92,7 +92,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -101,7 +101,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "7",
+   "id": "8",
    "metadata": {},
    "source": [
     "#### Set Unit Cell"
@@ -110,7 +110,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -121,7 +121,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "source": [
     "#### Set Atom Sites"
@@ -130,7 +130,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "10",
+   "id": "11",
    "metadata": {
     "lines_to_next_cell": 2
    },
@@ -143,7 +143,7 @@
     "    fract_y=0.25,\n",
     "    fract_z=0.167,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=1.37,\n",
+    "    adp_iso=1.37,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='S',\n",
@@ -152,7 +152,7 @@
     "    fract_y=0.25,\n",
     "    fract_z=0.684,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=0.3777,\n",
+    "    adp_iso=0.3777,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='O1',\n",
@@ -161,7 +161,7 @@
     "    fract_y=0.25,\n",
     "    fract_z=0.5954,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=1.9764,\n",
+    "    adp_iso=1.9764,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='O2',\n",
@@ -170,7 +170,7 @@
     "    fract_y=0.25,\n",
     "    fract_z=0.5432,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=1.4456,\n",
+    "    adp_iso=1.4456,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='O3',\n",
@@ -179,13 +179,13 @@
     "    fract_y=0.0272,\n",
     "    fract_z=0.8086,\n",
     "    wyckoff_letter='d',\n",
-    "    b_iso=1.2822,\n",
+    "    adp_iso=1.2822,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "source": [
     "## Define Experiments\n",
@@ -201,7 +201,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "12",
+   "id": "13",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -210,7 +210,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "13",
+   "id": "14",
    "metadata": {},
    "source": [
     "#### Create Experiment"
@@ -219,7 +219,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "14",
+   "id": "15",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -232,7 +232,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "15",
+   "id": "16",
    "metadata": {},
    "source": [
     "#### Set Instrument"
@@ -241,7 +241,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "16",
+   "id": "17",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -251,7 +251,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "17",
+   "id": "18",
    "metadata": {},
    "source": [
     "#### Set Peak Profile"
@@ -260,7 +260,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "18",
+   "id": "19",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -273,7 +273,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "19",
+   "id": "20",
    "metadata": {},
    "source": [
     "#### Set Background"
@@ -281,7 +281,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "20",
+   "id": "21",
    "metadata": {},
    "source": [
     "Select the background type."
@@ -290,7 +290,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "21",
+   "id": "22",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -299,7 +299,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "22",
+   "id": "23",
    "metadata": {},
    "source": [
     "Add background points."
@@ -308,7 +308,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "23",
+   "id": "24",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -327,7 +327,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "24",
+   "id": "25",
    "metadata": {},
    "source": [
     "#### Set Linked Phases"
@@ -336,7 +336,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "25",
+   "id": "26",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -345,7 +345,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "26",
+   "id": "27",
    "metadata": {},
    "source": [
     "### Experiment 2: xrd\n",
@@ -356,7 +356,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "27",
+   "id": "28",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -365,7 +365,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "28",
+   "id": "29",
    "metadata": {},
    "source": [
     "#### Create Experiment"
@@ -374,7 +374,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "29",
+   "id": "30",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -387,7 +387,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "30",
+   "id": "31",
    "metadata": {},
    "source": [
     "#### Set Instrument"
@@ -396,7 +396,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "31",
+   "id": "32",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -406,7 +406,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "32",
+   "id": "33",
    "metadata": {},
    "source": [
     "#### Set Peak Profile"
@@ -415,7 +415,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "33",
+   "id": "34",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -428,7 +428,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "34",
+   "id": "35",
    "metadata": {},
    "source": [
     "#### Set Background"
@@ -436,7 +436,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "35",
+   "id": "36",
    "metadata": {},
    "source": [
     "Select background type."
@@ -445,7 +445,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "36",
+   "id": "37",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -454,7 +454,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "37",
+   "id": "38",
    "metadata": {},
    "source": [
     "Add background points."
@@ -463,7 +463,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "38",
+   "id": "39",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -480,7 +480,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "39",
+   "id": "40",
    "metadata": {},
    "source": [
     "#### Set Linked Phases"
@@ -489,7 +489,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "40",
+   "id": "41",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -498,7 +498,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "41",
+   "id": "42",
    "metadata": {},
    "source": [
     "## Define Project\n",
@@ -512,7 +512,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "42",
+   "id": "43",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -521,7 +521,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "43",
+   "id": "44",
    "metadata": {},
    "source": [
     "#### Add Structure"
@@ -530,7 +530,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "44",
+   "id": "45",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -539,7 +539,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "45",
+   "id": "46",
    "metadata": {},
    "source": [
     "#### Add Experiments"
@@ -548,7 +548,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "46",
+   "id": "47",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -558,7 +558,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "47",
+   "id": "48",
    "metadata": {},
    "source": [
     "## Perform Analysis\n",
@@ -572,7 +572,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "48",
+   "id": "49",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -581,7 +581,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "49",
+   "id": "50",
    "metadata": {},
    "source": [
     "#### Set Minimizer"
@@ -590,7 +590,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "50",
+   "id": "51",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -599,7 +599,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "51",
+   "id": "52",
    "metadata": {},
    "source": [
     "#### Set Fitting Parameters\n",
@@ -610,7 +610,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "52",
+   "id": "53",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -621,7 +621,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "53",
+   "id": "54",
    "metadata": {},
    "source": [
     "Set experiment parameters to be optimized."
@@ -630,7 +630,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "54",
+   "id": "55",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -647,7 +647,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "55",
+   "id": "56",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -666,7 +666,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "56",
+   "id": "57",
    "metadata": {},
    "source": [
     "#### Perform Fit"
@@ -675,17 +675,18 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "57",
+   "id": "58",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.analysis.fit()\n",
-    "project.analysis.display.fit_results()"
+    "project.analysis.display.fit_results()\n",
+    "project.plotter.plot_param_correlations()"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "58",
+   "id": "59",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -694,7 +695,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "59",
+   "id": "60",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -704,7 +705,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "60",
+   "id": "61",
    "metadata": {},
    "outputs": [],
    "source": [
diff --git a/docs/docs/tutorials/ed-4.py b/docs/docs/tutorials/ed-4.py
index e2e1942bc..21bbaaada 100644
--- a/docs/docs/tutorials/ed-4.py
+++ b/docs/docs/tutorials/ed-4.py
@@ -56,7 +56,7 @@
     fract_y=0.25,
     fract_z=0.167,
     wyckoff_letter='c',
-    b_iso=1.37,
+    adp_iso=1.37,
 )
 structure.atom_sites.create(
     label='S',
@@ -65,7 +65,7 @@
     fract_y=0.25,
     fract_z=0.684,
     wyckoff_letter='c',
-    b_iso=0.3777,
+    adp_iso=0.3777,
 )
 structure.atom_sites.create(
     label='O1',
@@ -74,7 +74,7 @@
     fract_y=0.25,
     fract_z=0.5954,
     wyckoff_letter='c',
-    b_iso=1.9764,
+    adp_iso=1.9764,
 )
 structure.atom_sites.create(
     label='O2',
@@ -83,7 +83,7 @@
     fract_y=0.25,
     fract_z=0.5432,
     wyckoff_letter='c',
-    b_iso=1.4456,
+    adp_iso=1.4456,
 )
 structure.atom_sites.create(
     label='O3',
@@ -92,7 +92,7 @@
     fract_y=0.0272,
     fract_z=0.8086,
     wyckoff_letter='d',
-    b_iso=1.2822,
+    adp_iso=1.2822,
 )
 
 
@@ -314,6 +314,7 @@
 # %%
 project.analysis.fit()
 project.analysis.display.fit_results()
+project.plotter.plot_param_correlations()
 
 # %% [markdown]
 # #### Plot Measured vs Calculated
diff --git a/docs/docs/tutorials/ed-5.ipynb b/docs/docs/tutorials/ed-5.ipynb
index 9f4f53310..c78e3577d 100644
--- a/docs/docs/tutorials/ed-5.ipynb
+++ b/docs/docs/tutorials/ed-5.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "645a5335",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Structure Refinement: Co2SiO4, D20\n",
@@ -33,7 +33,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Import Library"
@@ -42,7 +42,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -54,7 +54,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Define Structure\n",
@@ -68,7 +68,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -77,7 +77,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "source": [
     "#### Set Space Group"
@@ -86,7 +86,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -96,7 +96,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "7",
+   "id": "8",
    "metadata": {},
    "source": [
     "#### Set Unit Cell"
@@ -105,7 +105,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -116,7 +116,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "source": [
     "#### Set Atom Sites"
@@ -125,7 +125,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "10",
+   "id": "11",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -136,7 +136,7 @@
     "    fract_y=0,\n",
     "    fract_z=0,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='Co2',\n",
@@ -145,7 +145,7 @@
     "    fract_y=0.25,\n",
     "    fract_z=0.985,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='Si',\n",
@@ -154,7 +154,7 @@
     "    fract_y=0.25,\n",
     "    fract_z=0.429,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='O1',\n",
@@ -163,7 +163,7 @@
     "    fract_y=0.25,\n",
     "    fract_z=0.771,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='O2',\n",
@@ -172,7 +172,7 @@
     "    fract_y=0.25,\n",
     "    fract_z=0.217,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='O3',\n",
@@ -181,13 +181,13 @@
     "    fract_y=0.032,\n",
     "    fract_z=0.28,\n",
     "    wyckoff_letter='d',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "source": [
     "## Define Experiment\n",
@@ -201,7 +201,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "12",
+   "id": "13",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -210,7 +210,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "13",
+   "id": "14",
    "metadata": {},
    "source": [
     "#### Create Experiment"
@@ -219,7 +219,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "14",
+   "id": "15",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -228,7 +228,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "15",
+   "id": "16",
    "metadata": {},
    "source": [
     "#### Set Instrument"
@@ -237,7 +237,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "16",
+   "id": "17",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -247,7 +247,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "17",
+   "id": "18",
    "metadata": {},
    "source": [
     "#### Set Peak Profile"
@@ -256,10 +256,11 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "18",
+   "id": "19",
    "metadata": {},
    "outputs": [],
    "source": [
+    "expt.peak_profile_type = 'pseudo-voigt + empirical asymmetry'\n",
     "expt.peak.broad_gauss_u = 0.3\n",
     "expt.peak.broad_gauss_v = -0.5\n",
     "expt.peak.broad_gauss_w = 0.4"
@@ -267,7 +268,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "19",
+   "id": "20",
    "metadata": {},
    "source": [
     "#### Set Background"
@@ -276,7 +277,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "20",
+   "id": "21",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -298,7 +299,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "21",
+   "id": "22",
    "metadata": {},
    "source": [
     "#### Set Linked Phases"
@@ -307,7 +308,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "22",
+   "id": "23",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -316,7 +317,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "23",
+   "id": "24",
    "metadata": {},
    "source": [
     "## Define Project\n",
@@ -330,7 +331,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "24",
+   "id": "25",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -339,28 +340,8 @@
   },
   {
    "cell_type": "markdown",
-   "id": "25",
-   "metadata": {},
-   "source": [
-    "#### Set Plotting Engine"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
    "id": "26",
    "metadata": {},
-   "outputs": [],
-   "source": [
-    "# Keep the auto-selected engine. Alternatively, you can uncomment the\n",
-    "# line below to explicitly set the engine to the required one.\n",
-    "# project.plotter.engine = 'plotly'"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "id": "27",
-   "metadata": {},
    "source": [
     "#### Add Structure"
    ]
@@ -368,7 +349,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "28",
+   "id": "27",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -377,7 +358,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "29",
+   "id": "28",
    "metadata": {},
    "source": [
     "#### Add Experiment"
@@ -386,7 +367,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "30",
+   "id": "29",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -395,7 +376,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "31",
+   "id": "30",
    "metadata": {},
    "source": [
     "## Perform Analysis\n",
@@ -409,7 +390,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "32",
+   "id": "31",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -418,7 +399,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "33",
+   "id": "32",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -427,7 +408,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "34",
+   "id": "33",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -437,7 +418,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "35",
+   "id": "34",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -446,7 +427,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "36",
+   "id": "35",
    "metadata": {},
    "source": [
     "#### Set Free Parameters"
@@ -455,7 +436,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "37",
+   "id": "36",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -475,18 +456,18 @@
     "structure.atom_sites['O3'].fract_y.free = True\n",
     "structure.atom_sites['O3'].fract_z.free = True\n",
     "\n",
-    "structure.atom_sites['Co1'].b_iso.free = True\n",
-    "structure.atom_sites['Co2'].b_iso.free = True\n",
-    "structure.atom_sites['Si'].b_iso.free = True\n",
-    "structure.atom_sites['O1'].b_iso.free = True\n",
-    "structure.atom_sites['O2'].b_iso.free = True\n",
-    "structure.atom_sites['O3'].b_iso.free = True"
+    "structure.atom_sites['Co1'].adp_iso.free = True\n",
+    "structure.atom_sites['Co2'].adp_iso.free = True\n",
+    "structure.atom_sites['Si'].adp_iso.free = True\n",
+    "structure.atom_sites['O1'].adp_iso.free = True\n",
+    "structure.atom_sites['O2'].adp_iso.free = True\n",
+    "structure.atom_sites['O3'].adp_iso.free = True"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "38",
+   "id": "37",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -499,13 +480,15 @@
     "expt.peak.broad_gauss_w.free = True\n",
     "expt.peak.broad_lorentz_y.free = True\n",
     "\n",
+    "expt.peak.asym_empir_2.free = True\n",
+    "\n",
     "for point in expt.background:\n",
     "    point.y.free = True"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "39",
+   "id": "38",
    "metadata": {},
    "source": [
     "#### Set Constraints\n",
@@ -516,23 +499,23 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "40",
+   "id": "39",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.analysis.aliases.create(\n",
     "    label='biso_Co1',\n",
-    "    param=project.structures['cosio'].atom_sites['Co1'].b_iso,\n",
+    "    param=project.structures['cosio'].atom_sites['Co1'].adp_iso,\n",
     ")\n",
     "project.analysis.aliases.create(\n",
     "    label='biso_Co2',\n",
-    "    param=project.structures['cosio'].atom_sites['Co2'].b_iso,\n",
+    "    param=project.structures['cosio'].atom_sites['Co2'].adp_iso,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "41",
+   "id": "40",
    "metadata": {},
    "source": [
     "Set constraints."
@@ -541,25 +524,33 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "42",
+   "id": "41",
    "metadata": {
     "lines_to_next_cell": 2
    },
    "outputs": [],
    "source": [
-    "project.analysis.constraints.create(\n",
-    "    expression='biso_Co2 = biso_Co1',\n",
-    ")"
+    "project.analysis.constraints.create(expression='biso_Co2 = biso_Co1')"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "43",
+   "id": "42",
    "metadata": {},
    "source": [
     "#### Run Fitting"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "43",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.analysis.fit()"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,
@@ -567,14 +558,23 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "project.analysis.fit()\n",
     "project.analysis.display.fit_results()"
    ]
   },
   {
-   "cell_type": "markdown",
+   "cell_type": "code",
+   "execution_count": null,
    "id": "45",
    "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.plotter.plot_param_correlations()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "46",
+   "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
    ]
@@ -582,7 +582,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "46",
+   "id": "47",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -592,7 +592,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "47",
+   "id": "48",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -601,7 +601,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "48",
+   "id": "49",
    "metadata": {},
    "source": [
     "## Summary\n",
@@ -611,7 +611,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "49",
+   "id": "50",
    "metadata": {},
    "source": [
     "#### Show Project Summary"
@@ -620,7 +620,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "50",
+   "id": "51",
    "metadata": {},
    "outputs": [],
    "source": [
diff --git a/docs/docs/tutorials/ed-5.py b/docs/docs/tutorials/ed-5.py
index 2938e50de..acd563699 100644
--- a/docs/docs/tutorials/ed-5.py
+++ b/docs/docs/tutorials/ed-5.py
@@ -51,7 +51,7 @@
     fract_y=0,
     fract_z=0,
     wyckoff_letter='a',
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 structure.atom_sites.create(
     label='Co2',
@@ -60,7 +60,7 @@
     fract_y=0.25,
     fract_z=0.985,
     wyckoff_letter='c',
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 structure.atom_sites.create(
     label='Si',
@@ -69,7 +69,7 @@
     fract_y=0.25,
     fract_z=0.429,
     wyckoff_letter='c',
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 structure.atom_sites.create(
     label='O1',
@@ -78,7 +78,7 @@
     fract_y=0.25,
     fract_z=0.771,
     wyckoff_letter='c',
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 structure.atom_sites.create(
     label='O2',
@@ -87,7 +87,7 @@
     fract_y=0.25,
     fract_z=0.217,
     wyckoff_letter='c',
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 structure.atom_sites.create(
     label='O3',
@@ -96,7 +96,7 @@
     fract_y=0.032,
     fract_z=0.28,
     wyckoff_letter='d',
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 
 # %% [markdown]
@@ -220,12 +220,12 @@
 structure.atom_sites['O3'].fract_y.free = True
 structure.atom_sites['O3'].fract_z.free = True
 
-structure.atom_sites['Co1'].b_iso.free = True
-structure.atom_sites['Co2'].b_iso.free = True
-structure.atom_sites['Si'].b_iso.free = True
-structure.atom_sites['O1'].b_iso.free = True
-structure.atom_sites['O2'].b_iso.free = True
-structure.atom_sites['O3'].b_iso.free = True
+structure.atom_sites['Co1'].adp_iso.free = True
+structure.atom_sites['Co2'].adp_iso.free = True
+structure.atom_sites['Si'].adp_iso.free = True
+structure.atom_sites['O1'].adp_iso.free = True
+structure.atom_sites['O2'].adp_iso.free = True
+structure.atom_sites['O3'].adp_iso.free = True
 
 # %%
 expt.linked_phases['cosio'].scale.free = True
@@ -250,11 +250,11 @@
 # %%
 project.analysis.aliases.create(
     label='biso_Co1',
-    param=project.structures['cosio'].atom_sites['Co1'].b_iso,
+    param=project.structures['cosio'].atom_sites['Co1'].adp_iso,
 )
 project.analysis.aliases.create(
     label='biso_Co2',
-    param=project.structures['cosio'].atom_sites['Co2'].b_iso,
+    param=project.structures['cosio'].atom_sites['Co2'].adp_iso,
 )
 
 # %% [markdown]
diff --git a/docs/docs/tutorials/ed-6.ipynb b/docs/docs/tutorials/ed-6.ipynb
index be47740f1..a2259fe9d 100644
--- a/docs/docs/tutorials/ed-6.ipynb
+++ b/docs/docs/tutorials/ed-6.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "fdc5cf61",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Structure Refinement: HS, HRPT\n",
@@ -33,7 +33,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Import Library"
@@ -42,7 +42,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -54,7 +54,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Define Structure\n",
@@ -68,7 +68,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -77,7 +77,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "source": [
     "#### Set Space Group"
@@ -86,7 +86,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -96,7 +96,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "7",
+   "id": "8",
    "metadata": {
     "lines_to_next_cell": 2
    },
@@ -107,7 +107,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -117,7 +117,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "source": [
     "#### Set Atom Sites"
@@ -126,7 +126,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "10",
+   "id": "11",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -137,7 +137,7 @@
     "    fract_y=0,\n",
     "    fract_z=0.5,\n",
     "    wyckoff_letter='b',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='Cu',\n",
@@ -146,7 +146,7 @@
     "    fract_y=0,\n",
     "    fract_z=0,\n",
     "    wyckoff_letter='e',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='O',\n",
@@ -155,7 +155,7 @@
     "    fract_y=-0.21,\n",
     "    fract_z=0.06,\n",
     "    wyckoff_letter='h',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='Cl',\n",
@@ -164,7 +164,7 @@
     "    fract_y=0,\n",
     "    fract_z=0.197,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='H',\n",
@@ -173,13 +173,13 @@
     "    fract_y=-0.13,\n",
     "    fract_z=0.08,\n",
     "    wyckoff_letter='h',\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "source": [
     "## Define Experiment\n",
@@ -193,7 +193,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "12",
+   "id": "13",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -202,7 +202,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "13",
+   "id": "14",
    "metadata": {},
    "source": [
     "#### Create Experiment"
@@ -211,7 +211,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "14",
+   "id": "15",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -220,7 +220,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "15",
+   "id": "16",
    "metadata": {},
    "source": [
     "#### Set Instrument"
@@ -229,7 +229,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "16",
+   "id": "17",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -239,7 +239,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "17",
+   "id": "18",
    "metadata": {},
    "source": [
     "#### Set Peak Profile"
@@ -248,7 +248,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "18",
+   "id": "19",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -261,7 +261,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "19",
+   "id": "20",
    "metadata": {},
    "source": [
     "#### Set Background"
@@ -270,7 +270,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "20",
+   "id": "21",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -287,7 +287,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "21",
+   "id": "22",
    "metadata": {},
    "source": [
     "#### Set Linked Phases"
@@ -296,7 +296,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "22",
+   "id": "23",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -305,7 +305,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "23",
+   "id": "24",
    "metadata": {},
    "source": [
     "## Define Project\n",
@@ -319,7 +319,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "24",
+   "id": "25",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -328,7 +328,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "25",
+   "id": "26",
    "metadata": {},
    "source": [
     "#### Set Plotting Engine"
@@ -337,7 +337,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "26",
+   "id": "27",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -348,7 +348,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "27",
+   "id": "28",
    "metadata": {},
    "source": [
     "#### Add Structure"
@@ -357,7 +357,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "28",
+   "id": "29",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -366,7 +366,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "29",
+   "id": "30",
    "metadata": {},
    "source": [
     "#### Add Experiment"
@@ -375,7 +375,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "30",
+   "id": "31",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -384,7 +384,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "31",
+   "id": "32",
    "metadata": {},
    "source": [
     "## Perform Analysis\n",
@@ -398,7 +398,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "32",
+   "id": "33",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -407,7 +407,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "33",
+   "id": "34",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -416,7 +416,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "34",
+   "id": "35",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -426,7 +426,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "35",
+   "id": "36",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -435,7 +435,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "36",
+   "id": "37",
    "metadata": {},
    "source": [
     "### Perform Fit 1/5\n",
@@ -446,7 +446,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "37",
+   "id": "38",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -459,7 +459,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "38",
+   "id": "39",
    "metadata": {},
    "source": [
     "Show free parameters after selection."
@@ -468,7 +468,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "39",
+   "id": "40",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -477,7 +477,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "40",
+   "id": "41",
    "metadata": {},
    "source": [
     "#### Run Fitting"
@@ -486,7 +486,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "41",
+   "id": "42",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -496,7 +496,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "42",
+   "id": "43",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -505,7 +505,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "43",
+   "id": "44",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -514,7 +514,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "44",
+   "id": "45",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -524,7 +524,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "45",
+   "id": "46",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -533,7 +533,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "46",
+   "id": "47",
    "metadata": {},
    "source": [
     "### Perform Fit 2/5\n",
@@ -544,7 +544,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "47",
+   "id": "48",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -559,7 +559,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "48",
+   "id": "49",
    "metadata": {},
    "source": [
     "Show free parameters after selection."
@@ -568,7 +568,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "49",
+   "id": "50",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -577,7 +577,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "50",
+   "id": "51",
    "metadata": {},
    "source": [
     "#### Run Fitting"
@@ -586,7 +586,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "51",
+   "id": "52",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -596,7 +596,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "52",
+   "id": "53",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -605,7 +605,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "53",
+   "id": "54",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -614,7 +614,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "54",
+   "id": "55",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -624,7 +624,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "55",
+   "id": "56",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -633,7 +633,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "56",
+   "id": "57",
    "metadata": {},
    "source": [
     "### Perform Fit 3/5\n",
@@ -644,7 +644,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "57",
+   "id": "58",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -657,7 +657,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "58",
+   "id": "59",
    "metadata": {},
    "source": [
     "Show free parameters after selection."
@@ -666,7 +666,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "59",
+   "id": "60",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -675,7 +675,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "60",
+   "id": "61",
    "metadata": {},
    "source": [
     "#### Run Fitting"
@@ -684,7 +684,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "61",
+   "id": "62",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -694,7 +694,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "62",
+   "id": "63",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -703,7 +703,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "63",
+   "id": "64",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -712,7 +712,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "64",
+   "id": "65",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -722,7 +722,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "65",
+   "id": "66",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -731,7 +731,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "66",
+   "id": "67",
    "metadata": {},
    "source": [
     "### Perform Fit 4/5\n",
@@ -742,20 +742,20 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "67",
+   "id": "68",
    "metadata": {},
    "outputs": [],
    "source": [
-    "structure.atom_sites['Zn'].b_iso.free = True\n",
-    "structure.atom_sites['Cu'].b_iso.free = True\n",
-    "structure.atom_sites['O'].b_iso.free = True\n",
-    "structure.atom_sites['Cl'].b_iso.free = True\n",
-    "structure.atom_sites['H'].b_iso.free = True"
+    "structure.atom_sites['Zn'].adp_iso.free = True\n",
+    "structure.atom_sites['Cu'].adp_iso.free = True\n",
+    "structure.atom_sites['O'].adp_iso.free = True\n",
+    "structure.atom_sites['Cl'].adp_iso.free = True\n",
+    "structure.atom_sites['H'].adp_iso.free = True"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "68",
+   "id": "69",
    "metadata": {},
    "source": [
     "Show free parameters after selection."
@@ -764,7 +764,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "69",
+   "id": "70",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -773,7 +773,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "70",
+   "id": "71",
    "metadata": {},
    "source": [
     "#### Run Fitting"
@@ -782,7 +782,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "71",
+   "id": "72",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -792,16 +792,26 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "72",
+   "id": "73",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.analysis.display.fit_results()"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "74",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.plotter.plot_param_correlations()"
+   ]
+  },
   {
    "cell_type": "markdown",
-   "id": "73",
+   "id": "75",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -810,7 +820,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "74",
+   "id": "76",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -820,7 +830,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "75",
+   "id": "77",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -829,7 +839,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "76",
+   "id": "78",
    "metadata": {},
    "source": [
     "## Summary\n",
@@ -839,7 +849,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "77",
+   "id": "79",
    "metadata": {},
    "source": [
     "#### Show Project Summary"
@@ -848,7 +858,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "78",
+   "id": "80",
    "metadata": {},
    "outputs": [],
    "source": [
diff --git a/docs/docs/tutorials/ed-6.py b/docs/docs/tutorials/ed-6.py
index 70c1c1948..20edc504c 100644
--- a/docs/docs/tutorials/ed-6.py
+++ b/docs/docs/tutorials/ed-6.py
@@ -51,7 +51,7 @@
     fract_y=0,
     fract_z=0.5,
     wyckoff_letter='b',
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 structure.atom_sites.create(
     label='Cu',
@@ -60,7 +60,7 @@
     fract_y=0,
     fract_z=0,
     wyckoff_letter='e',
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 structure.atom_sites.create(
     label='O',
@@ -69,7 +69,7 @@
     fract_y=-0.21,
     fract_z=0.06,
     wyckoff_letter='h',
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 structure.atom_sites.create(
     label='Cl',
@@ -78,7 +78,7 @@
     fract_y=0,
     fract_z=0.197,
     wyckoff_letter='c',
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 structure.atom_sites.create(
     label='H',
@@ -87,7 +87,7 @@
     fract_y=-0.13,
     fract_z=0.08,
     wyckoff_letter='h',
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 
 # %% [markdown]
@@ -311,11 +311,11 @@
 # Set more parameters to be refined.
 
 # %%
-structure.atom_sites['Zn'].b_iso.free = True
-structure.atom_sites['Cu'].b_iso.free = True
-structure.atom_sites['O'].b_iso.free = True
-structure.atom_sites['Cl'].b_iso.free = True
-structure.atom_sites['H'].b_iso.free = True
+structure.atom_sites['Zn'].adp_iso.free = True
+structure.atom_sites['Cu'].adp_iso.free = True
+structure.atom_sites['O'].adp_iso.free = True
+structure.atom_sites['Cl'].adp_iso.free = True
+structure.atom_sites['H'].adp_iso.free = True
 
 # %% [markdown]
 # Show free parameters after selection.
@@ -332,6 +332,9 @@
 # %%
 project.analysis.display.fit_results()
 
+# %%
+project.plotter.plot_param_correlations()
+
 # %% [markdown]
 # #### Plot Measured vs Calculated
 
diff --git a/docs/docs/tutorials/ed-7.ipynb b/docs/docs/tutorials/ed-7.ipynb
index b80018e28..bc9a57ed7 100644
--- a/docs/docs/tutorials/ed-7.ipynb
+++ b/docs/docs/tutorials/ed-7.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "e195a39c",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Structure Refinement: Si, SEPD\n",
@@ -33,7 +33,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Import Library"
@@ -42,7 +42,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -54,7 +54,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Define Structure\n",
@@ -68,7 +68,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -77,7 +77,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "source": [
     "#### Set Space Group"
@@ -86,7 +86,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -96,7 +96,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "7",
+   "id": "8",
    "metadata": {},
    "source": [
     "#### Set Unit Cell"
@@ -105,7 +105,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -114,7 +114,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "source": [
     "#### Set Atom Sites"
@@ -123,7 +123,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "10",
+   "id": "11",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -133,13 +133,13 @@
     "    fract_x=0.125,\n",
     "    fract_y=0.125,\n",
     "    fract_z=0.125,\n",
-    "    b_iso=0.5,\n",
+    "    adp_iso=0.5,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "source": [
     "## Define Experiment\n",
@@ -153,7 +153,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "12",
+   "id": "13",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -162,7 +162,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "13",
+   "id": "14",
    "metadata": {},
    "source": [
     "#### Create Experiment"
@@ -171,7 +171,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "14",
+   "id": "15",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -182,7 +182,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "15",
+   "id": "16",
    "metadata": {},
    "source": [
     "#### Set Instrument"
@@ -191,7 +191,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "16",
+   "id": "17",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -203,7 +203,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "17",
+   "id": "18",
    "metadata": {},
    "source": [
     "#### Set Peak Profile"
@@ -212,41 +212,24 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "18",
+   "id": "19",
    "metadata": {},
    "outputs": [],
    "source": [
-    "expt.peak_profile_type = 'pseudo-voigt * ikeda-carpenter'\n",
+    "expt.peak_profile_type = 'jorgensen'\n",
     "expt.peak.broad_gauss_sigma_0 = 3.0\n",
     "expt.peak.broad_gauss_sigma_1 = 40.0\n",
     "expt.peak.broad_gauss_sigma_2 = 2.0\n",
-    "expt.peak.broad_mix_beta_0 = 0.04221\n",
-    "expt.peak.broad_mix_beta_1 = 0.00946"
+    "expt.peak.exp_decay_beta_0 = 0.04221\n",
+    "expt.peak.exp_decay_beta_1 = 0.00946\n",
+    "expt.peak.exp_rise_alpha_0 = 0.0\n",
+    "expt.peak.exp_rise_alpha_1 = 0.5971"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "19",
-   "metadata": {},
-   "source": [
-    "#### Set Peak Asymmetry"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
    "id": "20",
    "metadata": {},
-   "outputs": [],
-   "source": [
-    "expt.peak.asym_alpha_0 = 0.0\n",
-    "expt.peak.asym_alpha_1 = 0.5971"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "id": "21",
-   "metadata": {},
    "source": [
     "#### Set Background"
    ]
@@ -254,7 +237,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "22",
+   "id": "21",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -265,7 +248,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "23",
+   "id": "22",
    "metadata": {},
    "source": [
     "#### Set Linked Phases"
@@ -274,7 +257,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "24",
+   "id": "23",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -283,7 +266,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "25",
+   "id": "24",
    "metadata": {},
    "source": [
     "## Define Project\n",
@@ -297,7 +280,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "26",
+   "id": "25",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -306,7 +289,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "27",
+   "id": "26",
    "metadata": {},
    "source": [
     "#### Add Structure"
@@ -315,7 +298,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "28",
+   "id": "27",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -324,7 +307,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "29",
+   "id": "28",
    "metadata": {},
    "source": [
     "#### Add Experiment"
@@ -333,7 +316,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "30",
+   "id": "29",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -342,7 +325,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "31",
+   "id": "30",
    "metadata": {},
    "source": [
     "## Perform Analysis\n",
@@ -356,7 +339,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "32",
+   "id": "31",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -365,7 +348,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "33",
+   "id": "32",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -374,7 +357,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "34",
+   "id": "33",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -384,7 +367,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "35",
+   "id": "34",
    "metadata": {},
    "source": [
     "### Perform Fit 1/5\n",
@@ -395,7 +378,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "36",
+   "id": "35",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -407,7 +390,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "37",
+   "id": "36",
    "metadata": {},
    "source": [
     "Show free parameters after selection."
@@ -416,7 +399,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "38",
+   "id": "37",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -425,7 +408,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "39",
+   "id": "38",
    "metadata": {},
    "source": [
     "#### Run Fitting"
@@ -434,7 +417,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "40",
+   "id": "39",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -444,7 +427,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "41",
+   "id": "40",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -453,7 +436,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "42",
+   "id": "41",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -463,7 +446,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "43",
+   "id": "42",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -472,7 +455,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "44",
+   "id": "43",
    "metadata": {},
    "source": [
     "### Perform Fit 2/5\n",
@@ -483,7 +466,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "45",
+   "id": "44",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -493,7 +476,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "46",
+   "id": "45",
    "metadata": {},
    "source": [
     "Show free parameters after selection."
@@ -502,7 +485,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "47",
+   "id": "46",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -511,7 +494,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "48",
+   "id": "47",
    "metadata": {},
    "source": [
     "#### Run Fitting"
@@ -520,7 +503,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "49",
+   "id": "48",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -530,7 +513,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "50",
+   "id": "49",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -539,7 +522,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "51",
+   "id": "50",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -549,7 +532,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "52",
+   "id": "51",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -558,7 +541,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "53",
+   "id": "52",
    "metadata": {},
    "source": [
     "### Perform Fit 3/5\n",
@@ -569,7 +552,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "54",
+   "id": "53",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -579,7 +562,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "55",
+   "id": "54",
    "metadata": {},
    "source": [
     "Set more parameters to be refined."
@@ -588,7 +571,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "56",
+   "id": "55",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -599,7 +582,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "57",
+   "id": "56",
    "metadata": {},
    "source": [
     "Show free parameters after selection."
@@ -608,7 +591,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "58",
+   "id": "57",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -617,7 +600,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "59",
+   "id": "58",
    "metadata": {},
    "source": [
     "#### Run Fitting"
@@ -626,7 +609,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "60",
+   "id": "59",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -636,7 +619,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "61",
+   "id": "60",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -645,7 +628,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "62",
+   "id": "61",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -655,7 +638,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "63",
+   "id": "62",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -664,7 +647,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "64",
+   "id": "63",
    "metadata": {},
    "source": [
     "### Perform Fit 4/5\n",
@@ -675,16 +658,20 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "65",
+   "id": "64",
    "metadata": {},
    "outputs": [],
    "source": [
-    "structure.atom_sites['Si'].b_iso.free = True"
+    "structure.atom_sites['Si'].adp_iso.free = True\n",
+    "\n",
+    "expt.peak.exp_decay_beta_0.free = True\n",
+    "expt.peak.exp_decay_beta_1.free = True\n",
+    "expt.peak.exp_rise_alpha_1.free = True"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "66",
+   "id": "65",
    "metadata": {},
    "source": [
     "Show free parameters after selection."
@@ -693,7 +680,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "67",
+   "id": "66",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -702,7 +689,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "68",
+   "id": "67",
    "metadata": {},
    "source": [
     "#### Run Fitting"
@@ -711,7 +698,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "69",
+   "id": "68",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -721,8 +708,26 @@
   },
   {
    "cell_type": "markdown",
+   "id": "69",
+   "metadata": {},
+   "source": [
+    "#### Show parameter correlations"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
    "id": "70",
    "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.plotter.plot_param_correlations()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "71",
+   "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
    ]
@@ -730,7 +735,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "71",
+   "id": "72",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -740,12 +745,22 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "72",
+   "id": "73",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.plotter.plot_meas_vs_calc(expt_name='sepd', x_min=23200, x_max=23700, show_residual=True)"
    ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "74",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "project.plotter.plot_meas_vs_calc(expt_name='sepd', x='d_spacing', show_residual=True)"
+   ]
   }
  ],
  "metadata": {
diff --git a/docs/docs/tutorials/ed-7.py b/docs/docs/tutorials/ed-7.py
index 8dc9415ab..9bc97488e 100644
--- a/docs/docs/tutorials/ed-7.py
+++ b/docs/docs/tutorials/ed-7.py
@@ -48,7 +48,7 @@
     fract_x=0.125,
     fract_y=0.125,
     fract_z=0.125,
-    b_iso=0.5,
+    adp_iso=0.5,
 )
 
 # %% [markdown]
@@ -256,7 +256,7 @@
 # Set more parameters to be refined.
 
 # %%
-structure.atom_sites['Si'].b_iso.free = True
+structure.atom_sites['Si'].adp_iso.free = True
 
 expt.peak.exp_decay_beta_0.free = True
 expt.peak.exp_decay_beta_1.free = True
diff --git a/docs/docs/tutorials/ed-8.ipynb b/docs/docs/tutorials/ed-8.ipynb
index 45a9f8381..e8b6006eb 100644
--- a/docs/docs/tutorials/ed-8.ipynb
+++ b/docs/docs/tutorials/ed-8.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "68e98133",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Structure Refinement: NCAF, WISH\n",
@@ -36,7 +36,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Import Library"
@@ -45,7 +45,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -57,7 +57,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Define Structure\n",
@@ -71,7 +71,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -80,7 +80,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "source": [
     "#### Set Space Group"
@@ -89,7 +89,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -99,7 +99,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "7",
+   "id": "8",
    "metadata": {},
    "source": [
     "#### Set Unit Cell"
@@ -108,7 +108,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -117,7 +117,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "source": [
     "#### Set Atom Sites"
@@ -126,7 +126,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "10",
+   "id": "11",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -137,7 +137,7 @@
     "    fract_y=0.0,\n",
     "    fract_z=0.25,\n",
     "    wyckoff_letter='b',\n",
-    "    b_iso=0.92,\n",
+    "    adp_iso=0.92,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='Al',\n",
@@ -146,7 +146,7 @@
     "    fract_y=0.2521,\n",
     "    fract_z=0.2521,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.73,\n",
+    "    adp_iso=0.73,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='Na',\n",
@@ -155,7 +155,7 @@
     "    fract_y=0.0851,\n",
     "    fract_z=0.0851,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=2.08,\n",
+    "    adp_iso=2.08,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='F1',\n",
@@ -164,7 +164,7 @@
     "    fract_y=0.3054,\n",
     "    fract_z=0.1195,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=0.90,\n",
+    "    adp_iso=0.90,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='F2',\n",
@@ -173,7 +173,7 @@
     "    fract_y=0.3633,\n",
     "    fract_z=0.1867,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=1.37,\n",
+    "    adp_iso=1.37,\n",
     ")\n",
     "structure.atom_sites.create(\n",
     "    label='F3',\n",
@@ -182,13 +182,13 @@
     "    fract_y=0.4612,\n",
     "    fract_z=0.4612,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.88,\n",
+    "    adp_iso=0.88,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "source": [
     "## Define Experiment\n",
@@ -202,7 +202,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "12",
+   "id": "13",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -212,7 +212,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "13",
+   "id": "14",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -221,7 +221,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "14",
+   "id": "15",
    "metadata": {},
    "source": [
     "#### Create Experiment"
@@ -230,7 +230,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "15",
+   "id": "16",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -244,7 +244,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "16",
+   "id": "17",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -257,7 +257,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "17",
+   "id": "18",
    "metadata": {},
    "source": [
     "#### Set Instrument"
@@ -266,7 +266,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "18",
+   "id": "19",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -279,7 +279,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "19",
+   "id": "20",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -291,7 +291,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "20",
+   "id": "21",
    "metadata": {},
    "source": [
     "#### Set Peak Profile"
@@ -300,38 +300,38 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "21",
+   "id": "22",
    "metadata": {},
    "outputs": [],
    "source": [
     "expt56.peak.broad_gauss_sigma_0 = 0.0\n",
     "expt56.peak.broad_gauss_sigma_1 = 0.0\n",
     "expt56.peak.broad_gauss_sigma_2 = 15.5\n",
-    "expt56.peak.broad_mix_beta_0 = 0.007\n",
-    "expt56.peak.broad_mix_beta_1 = 0.01\n",
-    "expt56.peak.asym_alpha_0 = -0.0094\n",
-    "expt56.peak.asym_alpha_1 = 0.1"
+    "expt56.peak.exp_decay_beta_0 = 0.007\n",
+    "expt56.peak.exp_decay_beta_1 = 0.01\n",
+    "expt56.peak.exp_rise_alpha_0 = -0.0094\n",
+    "expt56.peak.exp_rise_alpha_1 = 0.1"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "22",
+   "id": "23",
    "metadata": {},
    "outputs": [],
    "source": [
     "expt47.peak.broad_gauss_sigma_0 = 0.0\n",
     "expt47.peak.broad_gauss_sigma_1 = 29.8\n",
     "expt47.peak.broad_gauss_sigma_2 = 18.0\n",
-    "expt47.peak.broad_mix_beta_0 = 0.006\n",
-    "expt47.peak.broad_mix_beta_1 = 0.015\n",
-    "expt47.peak.asym_alpha_0 = -0.0115\n",
-    "expt47.peak.asym_alpha_1 = 0.1"
+    "expt47.peak.exp_decay_beta_0 = 0.006\n",
+    "expt47.peak.exp_decay_beta_1 = 0.015\n",
+    "expt47.peak.exp_rise_alpha_0 = -0.0115\n",
+    "expt47.peak.exp_rise_alpha_1 = 0.1"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "23",
+   "id": "24",
    "metadata": {},
    "source": [
     "#### Set Background"
@@ -340,7 +340,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "24",
+   "id": "25",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -384,7 +384,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "25",
+   "id": "26",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -426,7 +426,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "26",
+   "id": "27",
    "metadata": {},
    "source": [
     "#### Set Linked Phases"
@@ -435,7 +435,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "27",
+   "id": "28",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -445,7 +445,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "28",
+   "id": "29",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -454,7 +454,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "29",
+   "id": "30",
    "metadata": {},
    "source": [
     "#### Set Excluded Regions"
@@ -463,7 +463,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "30",
+   "id": "31",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -474,7 +474,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "31",
+   "id": "32",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -484,7 +484,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "32",
+   "id": "33",
    "metadata": {},
    "source": [
     "## Define Project\n",
@@ -498,7 +498,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "33",
+   "id": "34",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -507,7 +507,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "34",
+   "id": "35",
    "metadata": {},
    "source": [
     "#### Set Plotting Engine"
@@ -516,7 +516,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "35",
+   "id": "36",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -527,7 +527,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "36",
+   "id": "37",
    "metadata": {},
    "source": [
     "#### Add Structure"
@@ -536,7 +536,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "37",
+   "id": "38",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -545,7 +545,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "38",
+   "id": "39",
    "metadata": {},
    "source": [
     "#### Add Experiment"
@@ -554,7 +554,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "39",
+   "id": "40",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -564,7 +564,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "40",
+   "id": "41",
    "metadata": {},
    "source": [
     "## Perform Analysis\n",
@@ -578,7 +578,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "41",
+   "id": "42",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -587,7 +587,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "42",
+   "id": "43",
    "metadata": {},
    "source": [
     "#### Set Fit Mode"
@@ -596,7 +596,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "43",
+   "id": "44",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -605,7 +605,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "44",
+   "id": "45",
    "metadata": {},
    "source": [
     "#### Set Free Parameters"
@@ -614,22 +614,22 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "45",
+   "id": "46",
    "metadata": {},
    "outputs": [],
    "source": [
-    "structure.atom_sites['Ca'].b_iso.free = True\n",
-    "structure.atom_sites['Al'].b_iso.free = True\n",
-    "structure.atom_sites['Na'].b_iso.free = True\n",
-    "structure.atom_sites['F1'].b_iso.free = True\n",
-    "structure.atom_sites['F2'].b_iso.free = True\n",
-    "structure.atom_sites['F3'].b_iso.free = True"
+    "structure.atom_sites['Ca'].adp_iso.free = True\n",
+    "structure.atom_sites['Al'].adp_iso.free = True\n",
+    "structure.atom_sites['Na'].adp_iso.free = True\n",
+    "structure.atom_sites['F1'].adp_iso.free = True\n",
+    "structure.atom_sites['F2'].adp_iso.free = True\n",
+    "structure.atom_sites['F3'].adp_iso.free = True"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "46",
+   "id": "47",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -637,22 +637,22 @@
     "expt56.instrument.calib_d_to_tof_offset.free = True\n",
     "expt56.instrument.calib_d_to_tof_linear.free = True\n",
     "expt56.peak.broad_gauss_sigma_2.free = True\n",
-    "expt56.peak.broad_mix_beta_0.free = True\n",
-    "expt56.peak.broad_mix_beta_1.free = True\n",
-    "expt56.peak.asym_alpha_1.free = True\n",
+    "expt56.peak.exp_decay_beta_0.free = True\n",
+    "expt56.peak.exp_decay_beta_1.free = True\n",
+    "expt56.peak.exp_rise_alpha_1.free = True\n",
     "\n",
     "expt47.linked_phases['ncaf'].scale.free = True\n",
     "expt47.instrument.calib_d_to_tof_linear.free = True\n",
     "expt47.instrument.calib_d_to_tof_offset.free = True\n",
     "expt47.peak.broad_gauss_sigma_2.free = True\n",
-    "expt47.peak.broad_mix_beta_0.free = True\n",
-    "expt47.peak.broad_mix_beta_1.free = True\n",
-    "expt47.peak.asym_alpha_1.free = True"
+    "expt47.peak.exp_decay_beta_0.free = True\n",
+    "expt47.peak.exp_decay_beta_1.free = True\n",
+    "expt47.peak.exp_rise_alpha_1.free = True"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "47",
+   "id": "48",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -661,7 +661,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "48",
+   "id": "49",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -671,7 +671,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "49",
+   "id": "50",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -680,7 +680,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "50",
+   "id": "51",
    "metadata": {},
    "source": [
     "#### Run Fitting"
@@ -689,17 +689,18 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "51",
+   "id": "52",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.analysis.fit()\n",
-    "project.analysis.display.fit_results()"
+    "project.analysis.display.fit_results()\n",
+    "project.plotter.plot_param_correlations()"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "52",
+   "id": "53",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -708,7 +709,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "53",
+   "id": "54",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -718,7 +719,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "54",
+   "id": "55",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -727,7 +728,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "55",
+   "id": "56",
    "metadata": {},
    "source": [
     "## Summary\n",
@@ -737,7 +738,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "56",
+   "id": "57",
    "metadata": {},
    "source": [
     "#### Show Project Summary"
@@ -746,7 +747,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "57",
+   "id": "58",
    "metadata": {},
    "outputs": [],
    "source": [
diff --git a/docs/docs/tutorials/ed-8.py b/docs/docs/tutorials/ed-8.py
index 88c14698a..b933c27cd 100644
--- a/docs/docs/tutorials/ed-8.py
+++ b/docs/docs/tutorials/ed-8.py
@@ -52,7 +52,7 @@
     fract_y=0.0,
     fract_z=0.25,
     wyckoff_letter='b',
-    b_iso=0.92,
+    adp_iso=0.92,
 )
 structure.atom_sites.create(
     label='Al',
@@ -61,7 +61,7 @@
     fract_y=0.2521,
     fract_z=0.2521,
     wyckoff_letter='a',
-    b_iso=0.73,
+    adp_iso=0.73,
 )
 structure.atom_sites.create(
     label='Na',
@@ -70,7 +70,7 @@
     fract_y=0.0851,
     fract_z=0.0851,
     wyckoff_letter='a',
-    b_iso=2.08,
+    adp_iso=2.08,
 )
 structure.atom_sites.create(
     label='F1',
@@ -79,7 +79,7 @@
     fract_y=0.3054,
     fract_z=0.1195,
     wyckoff_letter='c',
-    b_iso=0.90,
+    adp_iso=0.90,
 )
 structure.atom_sites.create(
     label='F2',
@@ -88,7 +88,7 @@
     fract_y=0.3633,
     fract_z=0.1867,
     wyckoff_letter='c',
-    b_iso=1.37,
+    adp_iso=1.37,
 )
 structure.atom_sites.create(
     label='F3',
@@ -97,7 +97,7 @@
     fract_y=0.4612,
     fract_z=0.4612,
     wyckoff_letter='a',
-    b_iso=0.88,
+    adp_iso=0.88,
 )
 
 # %% [markdown]
@@ -316,12 +316,12 @@
 # #### Set Free Parameters
 
 # %%
-structure.atom_sites['Ca'].b_iso.free = True
-structure.atom_sites['Al'].b_iso.free = True
-structure.atom_sites['Na'].b_iso.free = True
-structure.atom_sites['F1'].b_iso.free = True
-structure.atom_sites['F2'].b_iso.free = True
-structure.atom_sites['F3'].b_iso.free = True
+structure.atom_sites['Ca'].adp_iso.free = True
+structure.atom_sites['Al'].adp_iso.free = True
+structure.atom_sites['Na'].adp_iso.free = True
+structure.atom_sites['F1'].adp_iso.free = True
+structure.atom_sites['F2'].adp_iso.free = True
+structure.atom_sites['F3'].adp_iso.free = True
 
 # %%
 expt56.linked_phases['ncaf'].scale.free = True
@@ -355,6 +355,7 @@
 # %%
 project.analysis.fit()
 project.analysis.display.fit_results()
+project.plotter.plot_param_correlations()
 
 # %% [markdown]
 # #### Plot Measured vs Calculated
diff --git a/docs/docs/tutorials/ed-9.ipynb b/docs/docs/tutorials/ed-9.ipynb
index 31579906e..be44e177c 100644
--- a/docs/docs/tutorials/ed-9.ipynb
+++ b/docs/docs/tutorials/ed-9.ipynb
@@ -3,7 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "f854b55b",
+   "id": "0",
    "metadata": {
     "tags": [
      "hide-in-docs"
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "0",
+   "id": "1",
    "metadata": {},
    "source": [
     "# Structure Refinement: LBCO+Si, McStas\n",
@@ -33,7 +33,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1",
+   "id": "2",
    "metadata": {},
    "source": [
     "## Import Library"
@@ -42,7 +42,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -54,7 +54,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3",
+   "id": "4",
    "metadata": {},
    "source": [
     "## Define Structures\n",
@@ -68,7 +68,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "4",
+   "id": "5",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -77,7 +77,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "5",
+   "id": "6",
    "metadata": {},
    "source": [
     "#### Set Space Group"
@@ -86,7 +86,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "6",
+   "id": "7",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -96,7 +96,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "7",
+   "id": "8",
    "metadata": {},
    "source": [
     "#### Set Unit Cell"
@@ -105,7 +105,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "8",
+   "id": "9",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -114,7 +114,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "9",
+   "id": "10",
    "metadata": {},
    "source": [
     "#### Set Atom Sites"
@@ -123,7 +123,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "10",
+   "id": "11",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -134,7 +134,7 @@
     "    fract_y=0,\n",
     "    fract_z=0,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.2,\n",
+    "    adp_iso=0.2,\n",
     "    occupancy=0.5,\n",
     ")\n",
     "structure_1.atom_sites.create(\n",
@@ -144,7 +144,7 @@
     "    fract_y=0,\n",
     "    fract_z=0,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.2,\n",
+    "    adp_iso=0.2,\n",
     "    occupancy=0.5,\n",
     ")\n",
     "structure_1.atom_sites.create(\n",
@@ -154,7 +154,7 @@
     "    fract_y=0.5,\n",
     "    fract_z=0.5,\n",
     "    wyckoff_letter='b',\n",
-    "    b_iso=0.2567,\n",
+    "    adp_iso=0.2567,\n",
     ")\n",
     "structure_1.atom_sites.create(\n",
     "    label='O',\n",
@@ -163,13 +163,13 @@
     "    fract_y=0.5,\n",
     "    fract_z=0.5,\n",
     "    wyckoff_letter='c',\n",
-    "    b_iso=1.4041,\n",
+    "    adp_iso=1.4041,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "11",
+   "id": "12",
    "metadata": {},
    "source": [
     "### Create Structure 2: Si"
@@ -178,7 +178,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "12",
+   "id": "13",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -187,7 +187,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "13",
+   "id": "14",
    "metadata": {},
    "source": [
     "#### Set Space Group"
@@ -196,7 +196,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "14",
+   "id": "15",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -206,7 +206,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "15",
+   "id": "16",
    "metadata": {},
    "source": [
     "#### Set Unit Cell"
@@ -215,7 +215,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "16",
+   "id": "17",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -224,7 +224,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "17",
+   "id": "18",
    "metadata": {},
    "source": [
     "#### Set Atom Sites"
@@ -233,7 +233,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "18",
+   "id": "19",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -244,13 +244,13 @@
     "    fract_y=0.0,\n",
     "    fract_z=0.0,\n",
     "    wyckoff_letter='a',\n",
-    "    b_iso=0.0,\n",
+    "    adp_iso=0.0,\n",
     ")"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "19",
+   "id": "20",
    "metadata": {},
    "source": [
     "## Define Experiment\n",
@@ -264,7 +264,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "20",
+   "id": "21",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -273,7 +273,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "21",
+   "id": "22",
    "metadata": {},
    "source": [
     "#### Create Experiment"
@@ -282,7 +282,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "22",
+   "id": "23",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -298,7 +298,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "23",
+   "id": "24",
    "metadata": {},
    "source": [
     "#### Set Instrument"
@@ -307,7 +307,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "24",
+   "id": "25",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -319,7 +319,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "25",
+   "id": "26",
    "metadata": {},
    "source": [
     "#### Set Peak Profile"
@@ -328,23 +328,23 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "26",
+   "id": "27",
    "metadata": {},
    "outputs": [],
    "source": [
-    "# experiment.peak_profile_type = 'pseudo-voigt * ikeda-carpenter'\n",
+    "# experiment.peak_profile_type = 'jorgensen'\n",
     "experiment.peak.broad_gauss_sigma_0 = 45137\n",
     "experiment.peak.broad_gauss_sigma_1 = -52394\n",
     "experiment.peak.broad_gauss_sigma_2 = 22998\n",
-    "experiment.peak.broad_mix_beta_0 = 0.0055\n",
-    "experiment.peak.broad_mix_beta_1 = 0.0041\n",
-    "experiment.peak.asym_alpha_0 = 0\n",
-    "experiment.peak.asym_alpha_1 = 0.0097"
+    "experiment.peak.exp_decay_beta_0 = 0.0055\n",
+    "experiment.peak.exp_decay_beta_1 = 0.0041\n",
+    "experiment.peak.exp_rise_alpha_0 = 0\n",
+    "experiment.peak.exp_rise_alpha_1 = 0.0097"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "27",
+   "id": "28",
    "metadata": {},
    "source": [
     "#### Set Background"
@@ -352,7 +352,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "28",
+   "id": "29",
    "metadata": {},
    "source": [
     "Select the background type."
@@ -361,7 +361,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "29",
+   "id": "30",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -370,7 +370,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "30",
+   "id": "31",
    "metadata": {},
    "source": [
     "Add background points."
@@ -379,7 +379,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "31",
+   "id": "32",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -400,7 +400,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "32",
+   "id": "33",
    "metadata": {},
    "source": [
     "#### Set Linked Phases"
@@ -409,7 +409,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "33",
+   "id": "34",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -419,7 +419,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "34",
+   "id": "35",
    "metadata": {},
    "source": [
     "## Define Project\n",
@@ -433,7 +433,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "35",
+   "id": "36",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -442,7 +442,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "36",
+   "id": "37",
    "metadata": {},
    "source": [
     "#### Add Structures"
@@ -451,7 +451,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "37",
+   "id": "38",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -461,7 +461,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "38",
+   "id": "39",
    "metadata": {},
    "source": [
     "#### Show Structures"
@@ -470,7 +470,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "39",
+   "id": "40",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -479,7 +479,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "40",
+   "id": "41",
    "metadata": {},
    "source": [
     "#### Add Experiments"
@@ -488,7 +488,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "41",
+   "id": "42",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -497,7 +497,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "42",
+   "id": "43",
    "metadata": {},
    "source": [
     "#### Set Excluded Regions\n",
@@ -508,7 +508,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "43",
+   "id": "44",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -517,7 +517,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "44",
+   "id": "45",
    "metadata": {},
    "source": [
     "Add excluded regions."
@@ -526,7 +526,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "45",
+   "id": "46",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -536,7 +536,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "46",
+   "id": "47",
    "metadata": {},
    "source": [
     "Show excluded regions."
@@ -545,7 +545,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "47",
+   "id": "48",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -554,7 +554,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "48",
+   "id": "49",
    "metadata": {},
    "source": [
     "Show measured data after adding excluded regions."
@@ -563,7 +563,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "49",
+   "id": "50",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -572,7 +572,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "50",
+   "id": "51",
    "metadata": {},
    "source": [
     "Show experiment as CIF."
@@ -581,7 +581,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "51",
+   "id": "52",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -590,7 +590,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "52",
+   "id": "53",
    "metadata": {},
    "source": [
     "## Perform Analysis\n",
@@ -604,7 +604,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "53",
+   "id": "54",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -613,7 +613,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "54",
+   "id": "55",
    "metadata": {},
    "source": [
     "#### Set Fitting Parameters\n",
@@ -624,20 +624,20 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "55",
+   "id": "56",
    "metadata": {},
    "outputs": [],
    "source": [
     "structure_1.cell.length_a.free = True\n",
-    "structure_1.atom_sites['Co'].b_iso.free = True\n",
-    "structure_1.atom_sites['O'].b_iso.free = True\n",
+    "structure_1.atom_sites['Co'].adp_iso.free = True\n",
+    "structure_1.atom_sites['O'].adp_iso.free = True\n",
     "\n",
     "structure_2.cell.length_a.free = True"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "56",
+   "id": "57",
    "metadata": {},
    "source": [
     "Set experiment parameters to be optimized."
@@ -646,7 +646,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "57",
+   "id": "58",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -657,9 +657,9 @@
     "experiment.peak.broad_gauss_sigma_1.free = True\n",
     "experiment.peak.broad_gauss_sigma_2.free = True\n",
     "\n",
-    "experiment.peak.asym_alpha_1.free = True\n",
-    "experiment.peak.broad_mix_beta_0.free = True\n",
-    "experiment.peak.broad_mix_beta_1.free = True\n",
+    "experiment.peak.exp_rise_alpha_1.free = True\n",
+    "experiment.peak.exp_decay_beta_0.free = True\n",
+    "experiment.peak.exp_decay_beta_1.free = True\n",
     "\n",
     "for point in experiment.background:\n",
     "    point.y.free = True"
@@ -667,7 +667,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "58",
+   "id": "59",
    "metadata": {},
    "source": [
     "#### Perform Fit"
@@ -676,17 +676,18 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "59",
+   "id": "60",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.analysis.fit()\n",
-    "project.analysis.display.fit_results()"
+    "project.analysis.display.fit_results()\n",
+    "project.plotter.plot_param_correlations()"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "60",
+   "id": "61",
    "metadata": {},
    "source": [
     "#### Plot Measured vs Calculated"
@@ -695,20 +696,12 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "61",
+   "id": "62",
    "metadata": {},
    "outputs": [],
    "source": [
     "project.plotter.plot_meas_vs_calc(expt_name='mcstas')"
    ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "62",
-   "metadata": {},
-   "outputs": [],
-   "source": []
   }
  ],
  "metadata": {
diff --git a/docs/docs/tutorials/ed-9.py b/docs/docs/tutorials/ed-9.py
index c2cd4c157..92a024512 100644
--- a/docs/docs/tutorials/ed-9.py
+++ b/docs/docs/tutorials/ed-9.py
@@ -49,7 +49,7 @@
     fract_y=0,
     fract_z=0,
     wyckoff_letter='a',
-    b_iso=0.2,
+    adp_iso=0.2,
     occupancy=0.5,
 )
 structure_1.atom_sites.create(
@@ -59,7 +59,7 @@
     fract_y=0,
     fract_z=0,
     wyckoff_letter='a',
-    b_iso=0.2,
+    adp_iso=0.2,
     occupancy=0.5,
 )
 structure_1.atom_sites.create(
@@ -69,7 +69,7 @@
     fract_y=0.5,
     fract_z=0.5,
     wyckoff_letter='b',
-    b_iso=0.2567,
+    adp_iso=0.2567,
 )
 structure_1.atom_sites.create(
     label='O',
@@ -78,7 +78,7 @@
     fract_y=0.5,
     fract_z=0.5,
     wyckoff_letter='c',
-    b_iso=1.4041,
+    adp_iso=1.4041,
 )
 
 # %% [markdown]
@@ -111,7 +111,7 @@
     fract_y=0.0,
     fract_z=0.0,
     wyckoff_letter='a',
-    b_iso=0.0,
+    adp_iso=0.0,
 )
 
 # %% [markdown]
@@ -275,8 +275,8 @@
 
 # %%
 structure_1.cell.length_a.free = True
-structure_1.atom_sites['Co'].b_iso.free = True
-structure_1.atom_sites['O'].b_iso.free = True
+structure_1.atom_sites['Co'].adp_iso.free = True
+structure_1.atom_sites['O'].adp_iso.free = True
 
 structure_2.cell.length_a.free = True
 
@@ -304,11 +304,10 @@
 # %%
 project.analysis.fit()
 project.analysis.display.fit_results()
+project.plotter.plot_param_correlations()
 
 # %% [markdown]
 # #### Plot Measured vs Calculated
 
 # %%
 project.plotter.plot_meas_vs_calc(expt_name='mcstas')
-
-# %%
diff --git a/docs/docs/user-guide/analysis-workflow/analysis.md b/docs/docs/user-guide/analysis-workflow/analysis.md
index 86dbaec79..7b1be89f9 100644
--- a/docs/docs/user-guide/analysis-workflow/analysis.md
+++ b/docs/docs/user-guide/analysis-workflow/analysis.md
@@ -273,11 +273,11 @@ An example of setting aliases for parameters in a structure:
 # Set aliases for the atomic displacement parameters
 project.analysis.aliases.create(
     label='biso_La',
-    param_uid=project.structures['lbco'].atom_sites['La'].b_iso.uid,
+    param_uid=project.structures['lbco'].atom_sites['La'].adp_iso.uid,
 )
 project.analysis.aliases.create(
     label='biso_Ba',
-    param_uid=project.structures['lbco'].atom_sites['Ba'].b_iso.uid,
+    param_uid=project.structures['lbco'].atom_sites['Ba'].adp_iso.uid,
 )
 
 # Set aliases for the occupancies of the atom sites
diff --git a/docs/docs/user-guide/analysis-workflow/model.md b/docs/docs/user-guide/analysis-workflow/model.md
index 95e309cdb..3227199d6 100644
--- a/docs/docs/user-guide/analysis-workflow/model.md
+++ b/docs/docs/user-guide/analysis-workflow/model.md
@@ -108,7 +108,7 @@ project.structures['nacl'].atom_sites.create(
     fract_y=0,
     fract_z=0,
     occupancy=1,
-    b_iso_or_equiv=0.5,
+    adp_iso=0.5,
 )
 project.structures['nacl'].atom_sites.create(
     label='Cl',
@@ -117,7 +117,7 @@ project.structures['nacl'].atom_sites.create(
     fract_y=0,
     fract_z=0.5,
     occupancy=1,
-    b_iso_or_equiv=0.5,
+    adp_iso=0.5,
 )
 ```
 
diff --git a/docs/docs/user-guide/first-steps.md b/docs/docs/user-guide/first-steps.md
index 2f443398f..82f1b9de1 100644
--- a/docs/docs/user-guide/first-steps.md
+++ b/docs/docs/user-guide/first-steps.md
@@ -143,16 +143,16 @@ their projects.
 An example of the output for the
 `project.analysis.display.how_to_access_parameters()` method is:
 
-|     | Code variable                                       | Unique ID for CIF                |
-| --- | --------------------------------------------------- | -------------------------------- |
-| 1   | project.structures['lbco'].atom_site['La'].adp_type | lbco.atom_site.La.ADP_type       |
-| 2   | project.structures['lbco'].atom_site['La'].b_iso    | lbco.atom_site.La.B_iso_or_equiv |
-| 3   | project.structures['lbco'].atom_site['La'].fract_x  | lbco.atom_site.La.fract_x        |
-| 4   | project.structures['lbco'].atom_site['La'].fract_y  | lbco.atom_site.La.fract_y        |
-| ... | ...                                                 | ...                              |
-| 59  | project.experiments['hrpt'].peak.broad_gauss_u      | hrpt.peak.broad_gauss_u          |
-| 60  | project.experiments['hrpt'].peak.broad_gauss_v      | hrpt.peak.broad_gauss_v          |
-| 61  | project.experiments['hrpt'].peak.broad_gauss_w      | hrpt.peak.broad_gauss_w          |
+|     | Code variable                                       | Unique ID for CIF          |
+| --- | --------------------------------------------------- | -------------------------- |
+| 1   | project.structures['lbco'].atom_site['La'].adp_type | lbco.atom_site.La.ADP_type |
+| 2   | project.structures['lbco'].atom_site['La'].adp_iso  | lbco.atom_site.La.adp_iso  |
+| 3   | project.structures['lbco'].atom_site['La'].fract_x  | lbco.atom_site.La.fract_x  |
+| 4   | project.structures['lbco'].atom_site['La'].fract_y  | lbco.atom_site.La.fract_y  |
+| ... | ...                                                 | ...                        |
+| 59  | project.experiments['hrpt'].peak.broad_gauss_u      | hrpt.peak.broad_gauss_u    |
+| 60  | project.experiments['hrpt'].peak.broad_gauss_v      | hrpt.peak.broad_gauss_v    |
+| 61  | project.experiments['hrpt'].peak.broad_gauss_w      | hrpt.peak.broad_gauss_w    |
 
 ### Supported plotters
 
diff --git a/docs/docs/user-guide/parameters.md b/docs/docs/user-guide/parameters.md
index 424619316..4b4da1016 100644
--- a/docs/docs/user-guide/parameters.md
+++ b/docs/docs/user-guide/parameters.md
@@ -13,9 +13,9 @@ reference, and it belongs to a specific category.
   of the CIF name to comply with Python naming conventions. For example,
   `name_H-M_alt` becomes `name_h_m`, replacing hyphens with underscores
   and using lowercase letters.
-- In rare cases, the EasyDiffraction name is a bit shorter, like `b_iso`
-  instead of CIF `B_iso_or_equiv`, to make the code a bit more
-  user-friendly.
+- In rare cases, the EasyDiffraction name is a bit shorter, like
+  `adp_iso` instead of CIF `B_iso_or_equiv` / `U_iso_or_equiv`, to make
+  the code a bit more user-friendly.
 - When there is no defined CIF name for a parameter, EasyDiffraction
   introduces its own name, which is used in the code as well as an
   equivalent CIF name to be placed in the custom CIF dictionary
@@ -106,7 +106,7 @@ EasyDiffraction.
     |                                                     | :material-map-marker: [fract_z][atom_site]                   | atom_sites['ID'].fract_z           |
     |                                                     | :material-format-color-fill: [occupancy][atom_site]          | atom_sites['ID'].occupancy         |
     |                                                     | :material-cursor-move: [adp_type][atom_site]                 | atom_sites['ID'].adp_type          |
-    |                                                     | :material-cursor-move: [b_iso][atom_site]                    | atom_sites['ID'].b_iso             |
+    |                                                     | :material-cursor-move: [adp_iso][atom_site]                  | atom_sites['ID'].adp_iso           |
     |                                                     | :material-reflect-horizontal: [multiplicity][atom_site]      | atom_sites['ID'].multiplicity      |
     |                                                     | :material-reflect-horizontal: [wyckoff_letter][atom_site]    | atom_sites['ID'].wyckoff_letter    |
 
@@ -129,7 +129,7 @@ EasyDiffraction.
     |                                                     | :material-map-marker: [fract_z][atom_site]                   | \_atom_site.fract_z                     | [coreCIF][1]{:.label-cif} |
     |                                                     | :material-format-color-fill: [occupancy][atom_site]          | \_atom_site.occupancy                   | [coreCIF][1]{:.label-cif} |
     |                                                     | :material-cursor-move: [adp_type][atom_site]                 | \_atom_site.ADP_type                    | [coreCIF][1]{:.label-cif} |
-    |                                                     | :material-cursor-move: [b_iso][atom_site]                    | \_atom_site.B_iso_or_equiv              | [coreCIF][1]{:.label-cif} |
+    |                                                     | :material-cursor-move: [adp_iso][atom_site]                  | \_atom_site.B_iso_or_equiv              | [coreCIF][1]{:.label-cif} |
     |                                                     | :material-reflect-horizontal: [multiplicity][atom_site]      | \_atom_site.site_symmetry_multiplicity  | [coreCIF][1]{:.label-cif} |
     |                                                     | :material-reflect-horizontal: [wyckoff_letter][atom_site]    | \_atom_site.Wyckoff_symbol              | [coreCIF][1]{:.label-cif} |
 
diff --git a/pixi.toml b/pixi.toml
index 6706f3c9f..824f18508 100644
--- a/pixi.toml
+++ b/pixi.toml
@@ -187,8 +187,8 @@ notebook-exec = 'python -m pytest --nbmake docs/docs/tutorials/ --nbmake-timeout
 
 notebook-prepare = { depends-on = [
   'notebook-convert',
-  'notebook-strip',
   'notebook-tweak',
+  'notebook-strip',
 ] }
 
 ########################
diff --git a/src/easydiffraction/analysis/calculators/crysfml.py b/src/easydiffraction/analysis/calculators/crysfml.py
index 1fcc4087b..4255ee41a 100644
--- a/src/easydiffraction/analysis/calculators/crysfml.py
+++ b/src/easydiffraction/analysis/calculators/crysfml.py
@@ -198,8 +198,8 @@ def _convert_structure_to_dict(  # noqa: PLR6301
                 '_fract_y': atom.fract_y.value,
                 '_fract_z': atom.fract_z.value,
                 '_occupancy': atom.occupancy.value,
-                '_adp_type': 'Biso',  # Assuming Biso for simplicity
-                '_B_iso_or_equiv': atom.b_iso.value,
+                '_adp_type': atom.adp_type.value,
+                '_B_iso_or_equiv': atom.adp_iso_as_b,
             }
             structure_dict[structure.name]['_atom_site'].append(atom_site)
 
@@ -222,9 +222,10 @@ def _convert_experiment_to_dict(  # noqa: PLR6301
         dict[str, Any]
             A dictionary representation of the experiment.
         """
-        expt_type = getattr(experiment, 'type', None)
-        instrument = getattr(experiment, 'instrument', None)
-        peak = getattr(experiment, 'peak', None)
+        attrs = type(experiment)._public_attrs()
+        expt_type = experiment.type if 'type' in attrs else None
+        instrument = experiment.instrument if 'instrument' in attrs else None
+        peak = experiment.peak if 'peak' in attrs else None
 
         x_data = experiment.data.x
         twotheta_min = float(x_data.min())
diff --git a/src/easydiffraction/analysis/calculators/cryspy.py b/src/easydiffraction/analysis/calculators/cryspy.py
index 83f9587a6..15eaf9da4 100644
--- a/src/easydiffraction/analysis/calculators/cryspy.py
+++ b/src/easydiffraction/analysis/calculators/cryspy.py
@@ -19,9 +19,54 @@
 
 try:
     import cryspy
+
+    # Patch cryspy bug: calc_power_dwf_aniso uses indices [0:9] of
+    # reduced_symm_elems for the rotation matrix, but the rotation
+    # actually starts at index 4 (layout: [b1,b2,b3,bd, R(3x3)]).
+    # This causes wrong Debye-Waller factors for all anisotropic atoms.
+    # Bug confirmed in cryspy 0.7.8, reported upstream.
+    from cryspy.A_functions_base import debye_waller_factor as _dwf_mod
     from cryspy.H_functions_global.function_1_cryspy_objects import str_to_globaln
     from cryspy.procedure_rhochi.rhochi_by_dictionary import rhochi_calc_chi_sq_by_dictionary
 
+    def _patched_calc_power_dwf_aniso(
+        index_hkl: np.ndarray,
+        beta: np.ndarray,
+        symm_elems_r: np.ndarray,
+        *,
+        flag_beta: bool = False,
+    ) -> tuple:
+        h, k, l = index_hkl[0], index_hkl[1], index_hkl[2]  # noqa: E741
+        r = symm_elems_r
+        h_s = h * r[4] + k * r[7] + l * r[10]
+        k_s = h * r[5] + k * r[8] + l * r[11]
+        l_s = h * r[6] + k * r[9] + l * r[12]
+        power = (
+            beta[0] * np.square(h_s)
+            + beta[1] * np.square(k_s)
+            + beta[2] * np.square(l_s)
+            + 2.0 * beta[3] * h_s * k_s
+            + 2.0 * beta[4] * h_s * l_s
+            + 2.0 * beta[5] * k_s * l_s
+        )
+        dder: dict = {}
+        if flag_beta:
+            ones_b = np.ones_like(beta[0])
+            dder['beta'] = np.stack(
+                [
+                    ones_b * np.square(h_s),
+                    ones_b * np.square(k_s),
+                    ones_b * np.square(l_s),
+                    ones_b * 2.0 * h_s * k_s,
+                    ones_b * 2.0 * h_s * l_s,
+                    ones_b * 2.0 * k_s * l_s,
+                ],
+                axis=0,
+            )
+        return power, dder
+
+    _dwf_mod.calc_power_dwf_aniso = _patched_calc_power_dwf_aniso
+
     # TODO: Add the following print to debug mode
     # print("✅ 'cryspy' calculation engine is successfully imported.")
 except ImportError:
@@ -55,22 +100,32 @@ def __init__(self) -> None:
         super().__init__()
         self._cryspy_dicts: dict[str, dict[str, Any]] = {}
         self._cached_peak_types: dict[str, str] = {}
+        self._cached_adp_types: dict[str, tuple[str, ...]] = {}
 
     def _invalidate_stale_cache(
         self,
         combined_name: str,
         experiment: ExperimentBase,
+        structure: Structure | None = None,
     ) -> None:
         """
-        Drop cached dict when experiment peak profile type changed.
+        Drop cached dict when experiment or structure config changed.
+
+        Checks both the peak profile type and the per-atom ADP types.
+        When either changes the cached dictionary is stale and must be
+        rebuilt from a fresh cryspy object.
         """
-        peak = getattr(experiment, 'peak', None)
-        if peak is None:
-            return
-        current_type = peak.type_info.tag
-        if self._cached_peak_types.get(combined_name) != current_type:
-            self._cryspy_dicts.pop(combined_name, None)
-        self._cached_peak_types[combined_name] = current_type
+        if 'peak' in type(experiment)._public_attrs():
+            current_type = experiment.peak.type_info.tag
+            if self._cached_peak_types.get(combined_name) != current_type:
+                self._cryspy_dicts.pop(combined_name, None)
+            self._cached_peak_types[combined_name] = current_type
+
+        if structure is not None:
+            current_adp = tuple(atom.adp_type.value for atom in structure.atom_sites)
+            if self._cached_adp_types.get(combined_name) != current_adp:
+                self._cryspy_dicts.pop(combined_name, None)
+            self._cached_adp_types[combined_name] = current_adp
 
     def calculate_structure_factors(
         self,
@@ -92,7 +147,7 @@ def calculate_structure_factors(
             Whether the calculation is called by a minimizer.
         """
         combined_name = f'{structure.name}_{experiment.name}'
-        self._invalidate_stale_cache(combined_name, experiment)
+        self._invalidate_stale_cache(combined_name, experiment, structure)
 
         if called_by_minimizer:
             if self._cryspy_dicts and combined_name in self._cryspy_dicts:
@@ -164,7 +219,7 @@ def calculate_pattern(
             list of floats.
         """
         combined_name = f'{structure.name}_{experiment.name}'
-        self._invalidate_stale_cache(combined_name, experiment)
+        self._invalidate_stale_cache(combined_name, experiment, structure)
 
         if called_by_minimizer:
             if self._cryspy_dicts and combined_name in self._cryspy_dicts:
@@ -280,10 +335,100 @@ def _update_structure_in_cryspy_dict(
         for idx, atom_site in enumerate(structure.atom_sites):
             cryspy_occ[idx] = atom_site.occupancy.value
 
-        # Atomic ADPs - Biso only for now
+        # Atomic ADPs - isotropic
+        # For anisotropic atoms the full ADP lives in the β tensor;
+        # setting b_iso to zero avoids double-counting in cryspy's DWF
+        # which sums both the isotropic and anisotropic contributions.
+        from easydiffraction.datablocks.structure.categories.atom_sites.enums import (  # noqa: PLC0415
+            AdpTypeEnum,
+        )
+
+        aniso_types = {AdpTypeEnum.BANI.value, AdpTypeEnum.UANI.value}
         cryspy_biso = cryspy_model_dict['atom_b_iso']
         for idx, atom_site in enumerate(structure.atom_sites):
-            cryspy_biso[idx] = atom_site.b_iso.value
+            if atom_site.adp_type.value in aniso_types:
+                cryspy_biso[idx] = 0.0
+            else:
+                cryspy_biso[idx] = atom_site.adp_iso_as_b
+
+        # Atomic ADPs - anisotropic (update β tensor when present)
+        if 'atom_beta' in cryspy_model_dict:
+            CryspyCalculator._update_aniso_beta(
+                cryspy_model_dict,
+                structure,
+            )
+
+    @staticmethod
+    def _update_aniso_beta(
+        cryspy_model_dict: dict[str, Any],
+        structure: Structure,
+    ) -> None:
+        """
+        Update cryspy ``atom_beta`` from anisotropic ADP values.
+
+        Converts B or U tensor components to cryspy's internal β
+        representation using β_ij = 2π²·U_ij·a*_i·a*_j.
+
+        Parameters
+        ----------
+        cryspy_model_dict : dict[str, Any]
+            The ``crystal_<name>`` sub-dict.
+        structure : Structure
+            The source structure.
+        """
+        from cryspy.A_functions_base.function_1_atomic_vibrations import (  # noqa: PLC0415
+            calc_beta_by_u,
+        )
+        from cryspy.A_functions_base.unit_cell import (  # noqa: PLC0415
+            calc_reciprocal_by_unit_cell_parameters,
+        )
+
+        from easydiffraction.datablocks.structure.categories.atom_sites.enums import (  # noqa: PLC0415
+            AdpTypeEnum,
+        )
+
+        aniso_index = cryspy_model_dict.get('atom_site_aniso_index')
+        if aniso_index is None:
+            return
+
+        cryspy_beta = cryspy_model_dict['atom_beta']
+        cell_params = cryspy_model_dict['unit_cell_parameters']
+
+        # Compute reciprocal lengths from cell parameters (with angles
+        # already in radians as stored by cryspy).
+        recip_params, _ = calc_reciprocal_by_unit_cell_parameters(cell_params)
+
+        class _CellLike:
+            reciprocal_length_a = recip_params[0]
+            reciprocal_length_b = recip_params[1]
+            reciprocal_length_c = recip_params[2]
+
+        cell_like = _CellLike()
+        factor = 8.0 * np.pi**2
+
+        for col, atom_idx in enumerate(aniso_index):
+            atom = list(structure.atom_sites)[atom_idx]
+            adp_enum = AdpTypeEnum(atom.adp_type.value)
+            if adp_enum not in {AdpTypeEnum.BANI, AdpTypeEnum.UANI}:
+                continue
+
+            aniso = structure.atom_site_aniso[atom.label.value]
+            u_vals = [
+                aniso.adp_11.value,
+                aniso.adp_22.value,
+                aniso.adp_33.value,
+                aniso.adp_12.value,
+                aniso.adp_13.value,
+                aniso.adp_23.value,
+            ]
+
+            # Convert to U if stored as B
+            if adp_enum == AdpTypeEnum.BANI:
+                u_vals = [v / factor for v in u_vals]
+
+            betas = calc_beta_by_u(u_vals, cell_like)
+            for k in range(6):
+                cryspy_beta[k][col] = betas[k]
 
     @staticmethod
     def _update_experiment_in_cryspy_dict(
@@ -395,13 +540,17 @@ def _recreate_cryspy_obj(
 
         return cryspy_obj
 
-    def _convert_structure_to_cryspy_cif(  # noqa: PLR6301
-        self,
-        structure: Structure,
-    ) -> str:
+    def _convert_structure_to_cryspy_cif(self, structure: Structure) -> str:
         """
         Convert a structure to a Cryspy CIF string.
 
+        CrysPy uses attribute names that match the CIF convention:
+        ``u_11`` for ``U_11``, ``b_11`` for ``B_11``, etc.  Its
+        ``apply_space_group_constraint`` always accesses ``u_11``
+        regardless of ``adp_type``.  To avoid mismatches the CIF sent to
+        cryspy always uses **U** notation: ``Biso`` ⟶ ``Uiso``, ``Bani``
+        ⟶ ``Uani``, values divided by 8π².
+
         Parameters
         ----------
         structure : Structure
@@ -412,7 +561,117 @@ def _convert_structure_to_cryspy_cif(  # noqa: PLR6301
         str
             The Cryspy CIF string representation of the structure.
         """
-        return structure.as_cif
+        saved = self._temporarily_convert_to_u_notation(structure)
+
+        try:
+            cif = structure.as_cif
+        finally:
+            self._restore_from_u_notation(structure, saved)
+
+        return cif
+
+    @staticmethod
+    def _temporarily_convert_to_u_notation(
+        structure: Structure,
+    ) -> list[tuple]:
+        """
+        Temporarily convert all B-convention atoms to U notation.
+
+        Returns saved state for later restoration.
+        """
+        from easydiffraction.datablocks.structure.categories.atom_sites.enums import (  # noqa: PLC0415
+            AdpTypeEnum,
+        )
+
+        factor = 8.0 * np.pi**2
+        suffixes = ('11', '22', '33', '12', '13', '23')
+        saved: list[tuple] = []
+
+        for atom in structure.atom_sites:
+            adp_enum = AdpTypeEnum(atom.adp_type.value)
+            is_b = adp_enum in {AdpTypeEnum.BISO, AdpTypeEnum.BANI}
+            if not is_b:
+                continue
+
+            orig_adp_type = atom._adp_type._value
+            orig_iso_val = atom._adp_iso._value
+            orig_iso_names = list(atom._adp_iso._cif_handler._names)
+
+            atom._adp_iso._value = orig_iso_val / factor
+            atom._adp_iso._cif_handler._names = [
+                '_atom_site.U_iso_or_equiv',
+                '_atom_site.B_iso_or_equiv',
+            ]
+
+            if adp_enum == AdpTypeEnum.BISO:
+                atom._adp_type._value = AdpTypeEnum.UISO.value
+                saved.append((atom, None, None, None, orig_adp_type, orig_iso_names, orig_iso_val))
+            else:
+                atom._adp_type._value = AdpTypeEnum.UANI.value
+                lbl = atom.label.value
+                if lbl in structure.atom_site_aniso:
+                    aniso = structure.atom_site_aniso[lbl]
+                else:
+                    aniso = None
+                if aniso is not None:
+                    orig_vals = []
+                    orig_names = []
+                    for s in suffixes:
+                        param = getattr(aniso, f'_adp_{s}')
+                        orig_vals.append(param._value)
+                        orig_names.append(list(param._cif_handler._names))
+                        param._value /= factor
+                        param._cif_handler._names = [
+                            f'_atom_site_aniso.U_{s}',
+                            f'_atom_site_aniso.B_{s}',
+                        ]
+                    saved.append((
+                        atom,
+                        aniso,
+                        orig_vals,
+                        orig_names,
+                        orig_adp_type,
+                        orig_iso_names,
+                        orig_iso_val,
+                    ))
+                else:
+                    saved.append((
+                        atom,
+                        None,
+                        None,
+                        None,
+                        orig_adp_type,
+                        orig_iso_names,
+                        orig_iso_val,
+                    ))
+
+        return saved
+
+    @staticmethod
+    def _restore_from_u_notation(
+        structure: Structure,  # noqa: ARG004
+        saved: list[tuple],
+    ) -> None:
+        """Restore original B-convention state after CIF generation."""
+        suffixes = ('11', '22', '33', '12', '13', '23')
+
+        for (
+            atom,
+            aniso,
+            orig_vals,
+            orig_names,
+            orig_adp_type,
+            orig_iso_names,
+            orig_iso_val,
+        ) in saved:
+            atom._adp_type._value = orig_adp_type
+            atom._adp_iso._value = orig_iso_val
+            atom._adp_iso._cif_handler._names = orig_iso_names
+            if aniso is not None and orig_vals is not None:
+                for s, val, names in zip(suffixes, orig_vals, orig_names, strict=False):
+                    param = getattr(aniso, f'_adp_{s}')
+                    param._value = val
+                    param._cif_handler._names = names
 
     def _convert_experiment_to_cryspy_cif(  # noqa: PLR6301
         self,
@@ -434,10 +693,11 @@ def _convert_experiment_to_cryspy_cif(  # noqa: PLR6301
         str
             The Cryspy CIF string representation of the experiment.
         """
-        expt_type = getattr(experiment, 'type', None)
-        instrument = getattr(experiment, 'instrument', None)
-        peak = getattr(experiment, 'peak', None)
-        extinction = getattr(experiment, 'extinction', None)
+        attrs = type(experiment)._public_attrs()
+        expt_type = experiment.type if 'type' in attrs else None
+        instrument = experiment.instrument if 'instrument' in attrs else None
+        peak = experiment.peak if 'peak' in attrs else None
+        extinction = experiment.extinction if 'extinction' in attrs else None
 
         cif_lines = [f'data_{experiment.name}']
 
diff --git a/src/easydiffraction/analysis/fitting.py b/src/easydiffraction/analysis/fitting.py
index 2b6e11ecd..a29062037 100644
--- a/src/easydiffraction/analysis/fitting.py
+++ b/src/easydiffraction/analysis/fitting.py
@@ -65,6 +65,13 @@ def fit(
             spec for parameters whose ``fit_min``/``fit_max`` are
             unbounded.
         """
+        # Enforce symmetry constraints (e.g. ADP) before collecting
+        # free parameters so that components fixed by site symmetry are
+        # excluded from the minimizer's parameter set.
+        for structure in structures:
+            structure._need_categories_update = True
+            structure._update_categories()
+
         expt_free_params: list[Parameter] = []
         for expt in experiments:
             expt_free_params.extend(
diff --git a/src/easydiffraction/core/guard.py b/src/easydiffraction/core/guard.py
index ff259d3fb..986b589b3 100644
--- a/src/easydiffraction/core/guard.py
+++ b/src/easydiffraction/core/guard.py
@@ -33,6 +33,10 @@ def __repr__(self) -> str:
 
     def __getattr__(self, key: str) -> None:
         """Raise a descriptive error for unknown attribute access."""
+        # Private/dunder lookups should not trigger diagnostics —
+        # raise AttributeError so getattr(obj, '_foo', default) works.
+        if key.startswith('_'):
+            raise AttributeError(key)
         cls = type(self)
         allowed = cls._public_attrs()
         if key not in allowed:
diff --git a/src/easydiffraction/core/singleton.py b/src/easydiffraction/core/singleton.py
index 3cfb67d46..59ade7c38 100644
--- a/src/easydiffraction/core/singleton.py
+++ b/src/easydiffraction/core/singleton.py
@@ -62,7 +62,7 @@ def set_aliases(self, aliases: object) -> None:
         Set the alias map (name → alias wrapper).
 
         Called when user registers parameter aliases like:
-        alias='biso_La', param=model.atom_sites['La'].b_iso
+        alias='biso_La', param=model.atom_sites['La'].adp_iso
         """
         self._alias_to_param = dict(aliases.items())
 
diff --git a/src/easydiffraction/crystallography/crystallography.py b/src/easydiffraction/crystallography/crystallography.py
index 525ac99a9..141f059f7 100644
--- a/src/easydiffraction/crystallography/crystallography.py
+++ b/src/easydiffraction/crystallography/crystallography.py
@@ -1,8 +1,11 @@
 # SPDX-FileCopyrightText: 2025 EasyScience contributors <https://github.com/easyscience>
 # SPDX-License-Identifier: BSD-3-Clause
 
+from fractions import Fraction
 from typing import Any
 
+import numpy as np
+from cryspy.A_functions_base.function_1_atomic_vibrations import vibration_constraints
 from cryspy.A_functions_base.function_2_space_group import get_crystal_system_by_it_number
 from cryspy.A_functions_base.function_2_space_group import get_it_number_by_name_hm_short
 from sympy import Expr
@@ -189,3 +192,312 @@ def apply_atom_site_symmetry_constraints(
 
     _apply_fract_constraints(atom_site, parsed_exprs)
     return atom_site
+
+
+# ------------------------------------------------------------------
+#  ADP symmetry constraints
+# ------------------------------------------------------------------
+
+
+def _parse_rotation_matrix(expr_str: str) -> tuple[np.ndarray, np.ndarray]:
+    """
+    Extract rotation and translation from a coordinate expression.
+
+    Parses a symmetry-equivalent position string such as ``'(-x+1/2, y,
+    -z+1/2)'`` into a 3x3 rotation matrix and a translation vector.
+
+    Parameters
+    ----------
+    expr_str : str
+        A single symmetry-equivalent position, e.g. ``'(x,y,z)'``.
+
+    Returns
+    -------
+    tuple[np.ndarray, np.ndarray]
+        rotation : (3, 3) integer array. translation : (3,) float array
+        (fractional).
+    """
+    inner = expr_str.strip().strip('()')
+    parts = [p.strip() for p in inner.split(',')]
+
+    rot = np.zeros((3, 3), dtype=int)
+    trans = np.zeros(3)
+
+    var_map = {'x': 0, 'y': 1, 'z': 2}
+    for row, part in enumerate(parts):
+        # Replace subtraction by addition of negative terms
+        normalized = part.replace('-', '+-')
+        tokens = [t for t in normalized.split('+') if t]
+        for token in tokens:
+            matched = False
+            for var, col in var_map.items():
+                if var in token:
+                    coeff_str = token.replace(var, '').strip()
+                    if coeff_str in {'', '+'}:
+                        coeff = 1
+                    elif coeff_str == '-':
+                        coeff = -1
+                    else:
+                        coeff = int(coeff_str)
+                    rot[row, col] = coeff
+                    matched = True
+                    break
+            if not matched:
+                trans[row] = float(Fraction(token))
+
+    return rot, trans
+
+
+def _get_general_position_ops(
+    it_number: int,
+    coord_code: str | None,
+) -> list[tuple[np.ndarray, np.ndarray]] | None:
+    """
+    Return rotation matrices and translations for the general position.
+
+    Parameters
+    ----------
+    it_number : int
+        International Tables space group number.
+    coord_code : str | None
+        IT coordinate system code.
+
+    Returns
+    -------
+    list[tuple[np.ndarray, np.ndarray]] | None
+        List of (rotation, translation) pairs, or ``None`` on failure.
+    """
+    key = (it_number, coord_code)
+    if key not in SPACE_GROUPS:
+        log.error(f'Space group ({it_number}, {coord_code!r}) not found')
+        return None
+
+    entry = SPACE_GROUPS[key]
+    wyckoff_positions = entry['Wyckoff_positions']
+    # General position is the first key (highest multiplicity)
+    general_letter = next(iter(wyckoff_positions))
+    general_coords = wyckoff_positions[general_letter]['coords_xyz']
+    return [_parse_rotation_matrix(c) for c in general_coords]
+
+
+def _site_stabilizer_rotations(
+    ops: list[tuple[np.ndarray, np.ndarray]],
+    site_coords: tuple[float, float, float],
+) -> list[np.ndarray]:
+    """
+    Return rotation matrices of operations that leave a site invariant.
+
+    An operation (R, t) stabilises a site r when R·r + t ≡ r (mod 1).
+
+    Parameters
+    ----------
+    ops : list[tuple[np.ndarray, np.ndarray]]
+        All space group operations as (rotation, translation) pairs.
+    site_coords : tuple[float, float, float]
+        Fractional coordinates of the site.
+
+    Returns
+    -------
+    list[np.ndarray]
+        Rotation matrices of stabiliser operations.
+    """
+    r = np.array(site_coords, dtype=float)
+    stabiliser = []
+    for rot, trans in ops:
+        image = rot @ r + trans
+        diff = image - r
+        diff_mod = diff - np.round(diff)
+        if np.allclose(diff_mod, 0.0, atol=1e-6):
+            stabiliser.append(rot)
+    return stabiliser
+
+
+def _calc_adp_constraint_number(stabiliser: list[np.ndarray]) -> int:
+    """
+    Derive ADP constraint type via the Peterse-Palm probe technique.
+
+    A set of coprime probe values is transformed by each site-stabiliser
+    rotation (Acta Cryst. 1966, 20, 147).  The algebraic relationships
+    among the summed transformed components uniquely identify one of 19
+    constraint types (0 = no constraint, 1-18 as defined in cryspy's
+    ``vibration_constraints``).
+
+    Parameters
+    ----------
+    stabiliser : list[np.ndarray]
+        Rotation matrices of the site-stabiliser group.
+
+    Returns
+    -------
+    int
+        Constraint type number (0-18).
+    """
+    # Peterse-Palm probe values (coprime, pairwise distinct)
+    b_vals = np.array([107, 181, 41, 7, 19, 1], dtype=float)
+    b_matrix = np.array([
+        [b_vals[0], b_vals[3], b_vals[4]],
+        [b_vals[3], b_vals[1], b_vals[5]],
+        [b_vals[4], b_vals[5], b_vals[2]],
+    ])
+
+    accumulated = np.zeros((3, 3))
+    for rot in stabiliser:
+        accumulated += rot @ b_matrix @ rot.T
+
+    r_11 = round(accumulated[0, 0])
+    r_22 = round(accumulated[1, 1])
+    r_33 = round(accumulated[2, 2])
+    r_12 = round(accumulated[0, 1])
+    r_13 = round(accumulated[0, 2])
+    r_23 = round(accumulated[1, 2])
+
+    return _classify_constraint(r_11, r_22, r_33, r_12, r_13, r_23)
+
+
+def _classify_constraint(
+    r_11: int,
+    r_22: int,
+    r_33: int,
+    r_12: int,
+    r_13: int,
+    r_23: int,
+) -> int:
+    """
+    Map Peterse-Palm probe sums to a constraint type number.
+
+    Rule table follows cryspy (Peterse & Palm, Acta Cryst. 1966).
+
+    Parameters
+    ----------
+    r_11 : int
+        Accumulated probe-tensor component (1,1).
+    r_22 : int
+        Accumulated probe-tensor component (2,2).
+    r_33 : int
+        Accumulated probe-tensor component (3,3).
+    r_12 : int
+        Accumulated probe-tensor component (1,2).
+    r_13 : int
+        Accumulated probe-tensor component (1,3).
+    r_23 : int
+        Accumulated probe-tensor component (2,3).
+
+    Returns
+    -------
+    int
+        Constraint type (0-18).
+    """
+    z13 = r_13 == 0
+    z23 = r_23 == 0
+    z12 = r_12 == 0
+    eq_11_22 = r_11 == r_22
+    eq_22_33 = r_22 == r_33
+    eq_22_2x12 = r_22 == 2 * r_12
+    eq_23_13 = r_23 == r_13
+    eq_12_13 = r_12 == r_13
+    neg_23_13 = r_23 == -r_13
+
+    # Ordered from most specific to least; first match wins.
+    rules = [
+        (z13 and z23 and z12 and eq_11_22 and eq_22_33, 17),
+        (z13 and z23 and z12 and eq_11_22, 8),
+        (z13 and z23 and z12 and eq_22_33, 12),
+        (z13 and z23 and z12, 4),
+        (z13 and z23 and eq_11_22 and eq_22_2x12, 16),
+        (z13 and z23 and eq_11_22, 5),
+        (z13 and z23 and eq_22_2x12, 14),
+        (z13 and z23, 2),
+        (z13 and eq_22_33, 9),
+        (z13, 3),
+        (z23 and eq_22_2x12, 13),
+        (z23, 1),
+        (eq_23_13 and eq_22_33, 18),
+        (eq_23_13, 6),
+        (eq_12_13, 10),
+        (neg_23_13, 7),
+        (eq_22_33, 11),
+        (eq_22_2x12, 15),
+    ]
+    for condition, result in rules:
+        if condition:
+            return result
+    return 0
+
+
+def apply_atom_site_aniso_symmetry_constraints(
+    atom_site_aniso: dict[str, float],
+    name_hm: str,
+    coord_code: str | None,
+    _wyckoff_letter: str,
+    site_fract: tuple[float, float, float],
+) -> tuple[dict[str, float], tuple[bool, ...]]:
+    """
+    Apply symmetry constraints to anisotropic ADP tensor components.
+
+    Uses the Peterse-Palm probe technique to determine which tensor
+    components are constrained by the site symmetry, then delegates to
+    cryspy's ``vibration_constraints`` to enforce them.
+
+    Parameters
+    ----------
+    atom_site_aniso : dict[str, float]
+        Dictionary with keys ``'adp_11'`` … ``'adp_23'``.  Modified in
+        place.
+    name_hm : str
+        Hermann-Mauguin symbol of the space group.
+    coord_code : str | None
+        IT coordinate system code.
+    _wyckoff_letter : str
+        Wyckoff position letter (unused, reserved).
+    site_fract : tuple[float, float, float]
+        Fractional coordinates of the atom site.
+
+    Returns
+    -------
+    tuple[dict[str, float], tuple[bool, ...]]
+        The *atom_site_aniso* dictionary with constrained values, and a
+        6-tuple of booleans indicating which components remain free for
+        refinement (``True`` = free, ``False`` = fixed by symmetry).
+    """
+    all_free = (True, True, True, True, True, True)
+
+    it_number = get_it_number_by_name_hm_short(name_hm)
+    if it_number is None:
+        log.error(f"Failed to get IT_number for name_H-M '{name_hm}'")
+        return atom_site_aniso, all_free
+
+    ops = _get_general_position_ops(it_number, coord_code)
+    if ops is None:
+        return atom_site_aniso, all_free
+
+    stabiliser = _site_stabilizer_rotations(ops, site_fract)
+    if len(stabiliser) <= 1:
+        # Identity only — no ADP constraints
+        return atom_site_aniso, all_free
+
+    numb = _calc_adp_constraint_number(stabiliser)
+    if numb == 0:
+        return atom_site_aniso, all_free
+
+    param_i = (
+        atom_site_aniso['adp_11'],
+        atom_site_aniso['adp_22'],
+        atom_site_aniso['adp_33'],
+        atom_site_aniso['adp_12'],
+        atom_site_aniso['adp_13'],
+        atom_site_aniso['adp_23'],
+    )
+    sigma_i = (0.0, 0.0, 0.0, 0.0, 0.0, 0.0)
+    ref_i = (True, True, True, True, True, True)
+
+    param_i, _sigma_i, ref_i, _constr_i = vibration_constraints(
+        numb,
+        param_i,
+        sigma_i,
+        ref_i,
+    )
+
+    keys = ('adp_11', 'adp_22', 'adp_33', 'adp_12', 'adp_13', 'adp_23')
+    atom_site_aniso.update(dict(zip(keys, param_i, strict=False)))
+
+    return atom_site_aniso, ref_i
diff --git a/src/easydiffraction/datablocks/structure/categories/atom_site_aniso/__init__.py b/src/easydiffraction/datablocks/structure/categories/atom_site_aniso/__init__.py
new file mode 100644
index 000000000..fc8393f27
--- /dev/null
+++ b/src/easydiffraction/datablocks/structure/categories/atom_site_aniso/__init__.py
@@ -0,0 +1,7 @@
+# SPDX-FileCopyrightText: 2026 EasyScience contributors <https://github.com/easyscience>
+# SPDX-License-Identifier: BSD-3-Clause
+
+from easydiffraction.datablocks.structure.categories.atom_site_aniso.default import AtomSiteAniso
+from easydiffraction.datablocks.structure.categories.atom_site_aniso.default import (
+    AtomSiteAnisoCollection,
+)
diff --git a/src/easydiffraction/datablocks/structure/categories/atom_site_aniso/default.py b/src/easydiffraction/datablocks/structure/categories/atom_site_aniso/default.py
new file mode 100644
index 000000000..baa1dd675
--- /dev/null
+++ b/src/easydiffraction/datablocks/structure/categories/atom_site_aniso/default.py
@@ -0,0 +1,283 @@
+# SPDX-FileCopyrightText: 2026 EasyScience contributors <https://github.com/easyscience>
+# SPDX-License-Identifier: BSD-3-Clause
+"""
+Anisotropic ADP category.
+
+Defines :class:`AtomSiteAniso` items and
+:class:`AtomSiteAnisoCollection` used alongside :class:`AtomSites` to
+hold anisotropic displacement parameters.
+"""
+
+from __future__ import annotations
+
+from easydiffraction.core.category import CategoryCollection
+from easydiffraction.core.category import CategoryItem
+from easydiffraction.core.metadata import TypeInfo
+from easydiffraction.core.validation import AttributeSpec
+from easydiffraction.core.validation import RangeValidator
+from easydiffraction.core.variable import Parameter
+from easydiffraction.core.variable import StringDescriptor
+from easydiffraction.datablocks.structure.categories.atom_site_aniso.factory import (
+    AtomSiteAnisoFactory,
+)
+from easydiffraction.io.cif.handler import CifHandler
+
+
+class AtomSiteAniso(CategoryItem):
+    """
+    Single atom site anisotropic ADP entry.
+
+    Each entry mirrors an :class:`AtomSite` by label and holds six
+    tensor components whose physical meaning (B or U) is determined by
+    ``atom_site.adp_type``.
+    """
+
+    def __init__(self) -> None:
+        """Initialise with default zero-valued tensor components."""
+        super().__init__()
+
+        self._label = StringDescriptor(
+            name='label',
+            description='Atom-site label matching the parent atom_site entry.',
+            value_spec=AttributeSpec(default=''),
+            cif_handler=CifHandler(names=['_atom_site_aniso.label']),
+        )
+
+        self._adp_11 = Parameter(
+            name='adp_11',
+            description='Anisotropic ADP tensor component (1,1).',
+            units='Ų',
+            value_spec=AttributeSpec(
+                default=0.0,
+                validator=RangeValidator(),
+            ),
+            cif_handler=CifHandler(
+                names=[
+                    '_atom_site_aniso.B_11',
+                    '_atom_site_aniso.U_11',
+                ]
+            ),
+        )
+        self._adp_22 = Parameter(
+            name='adp_22',
+            description='Anisotropic ADP tensor component (2,2).',
+            units='Ų',
+            value_spec=AttributeSpec(
+                default=0.0,
+                validator=RangeValidator(),
+            ),
+            cif_handler=CifHandler(
+                names=[
+                    '_atom_site_aniso.B_22',
+                    '_atom_site_aniso.U_22',
+                ]
+            ),
+        )
+        self._adp_33 = Parameter(
+            name='adp_33',
+            description='Anisotropic ADP tensor component (3,3).',
+            units='Ų',
+            value_spec=AttributeSpec(
+                default=0.0,
+                validator=RangeValidator(),
+            ),
+            cif_handler=CifHandler(
+                names=[
+                    '_atom_site_aniso.B_33',
+                    '_atom_site_aniso.U_33',
+                ]
+            ),
+        )
+        self._adp_12 = Parameter(
+            name='adp_12',
+            description='Anisotropic ADP tensor component (1,2).',
+            units='Ų',
+            value_spec=AttributeSpec(
+                default=0.0,
+                validator=RangeValidator(),
+            ),
+            cif_handler=CifHandler(
+                names=[
+                    '_atom_site_aniso.B_12',
+                    '_atom_site_aniso.U_12',
+                ]
+            ),
+        )
+        self._adp_13 = Parameter(
+            name='adp_13',
+            description='Anisotropic ADP tensor component (1,3).',
+            units='Ų',
+            value_spec=AttributeSpec(
+                default=0.0,
+                validator=RangeValidator(),
+            ),
+            cif_handler=CifHandler(
+                names=[
+                    '_atom_site_aniso.B_13',
+                    '_atom_site_aniso.U_13',
+                ]
+            ),
+        )
+        self._adp_23 = Parameter(
+            name='adp_23',
+            description='Anisotropic ADP tensor component (2,3).',
+            units='Ų',
+            value_spec=AttributeSpec(
+                default=0.0,
+                validator=RangeValidator(),
+            ),
+            cif_handler=CifHandler(
+                names=[
+                    '_atom_site_aniso.B_23',
+                    '_atom_site_aniso.U_23',
+                ]
+            ),
+        )
+
+        self._identity.category_code = 'atom_site_aniso'
+        self._identity.category_entry_name = lambda: str(self.label.value)
+
+    # ------------------------------------------------------------------
+    #  Public properties
+    # ------------------------------------------------------------------
+
+    @property
+    def label(self) -> StringDescriptor:
+        """Label matching the parent atom_site entry."""
+        return self._label
+
+    @label.setter
+    def label(self, value: str) -> None:
+        self._label.value = value
+
+    @property
+    def adp_11(self) -> Parameter:
+        """Anisotropic ADP tensor component (1,1) in Ų."""
+        return self._adp_11
+
+    @adp_11.setter
+    def adp_11(self, value: float) -> None:
+        self._adp_11.value = value
+
+    @property
+    def adp_22(self) -> Parameter:
+        """Anisotropic ADP tensor component (2,2) in Ų."""
+        return self._adp_22
+
+    @adp_22.setter
+    def adp_22(self, value: float) -> None:
+        self._adp_22.value = value
+
+    @property
+    def adp_33(self) -> Parameter:
+        """Anisotropic ADP tensor component (3,3) in Ų."""
+        return self._adp_33
+
+    @adp_33.setter
+    def adp_33(self, value: float) -> None:
+        self._adp_33.value = value
+
+    @property
+    def adp_12(self) -> Parameter:
+        """Anisotropic ADP tensor component (1,2) in Ų."""
+        return self._adp_12
+
+    @adp_12.setter
+    def adp_12(self, value: float) -> None:
+        self._adp_12.value = value
+
+    @property
+    def adp_13(self) -> Parameter:
+        """Anisotropic ADP tensor component (1,3) in Ų."""
+        return self._adp_13
+
+    @adp_13.setter
+    def adp_13(self, value: float) -> None:
+        self._adp_13.value = value
+
+    @property
+    def adp_23(self) -> Parameter:
+        """Anisotropic ADP tensor component (2,3) in Ų."""
+        return self._adp_23
+
+    @adp_23.setter
+    def adp_23(self, value: float) -> None:
+        self._adp_23.value = value
+
+
+@AtomSiteAnisoFactory.register
+class AtomSiteAnisoCollection(CategoryCollection):
+    """Collection of :class:`AtomSiteAniso` instances."""
+
+    type_info = TypeInfo(
+        tag='default',
+        description='Anisotropic ADP collection',
+    )
+
+    def __init__(self) -> None:
+        """Initialise an empty aniso-ADP collection."""
+        super().__init__(item_type=AtomSiteAniso)
+
+    def _skip_cif_serialization(self) -> bool:
+        """
+        Return ``True`` when no atoms use an anisotropic ADP type.
+
+        Returns
+        -------
+        bool
+            ``True`` if CIF output should be suppressed.
+        """
+        structure = getattr(self, '_parent', None)
+        if structure is None:
+            return True
+        atom_sites = getattr(structure, '_atom_sites', None)
+        if atom_sites is None:
+            return True
+        from easydiffraction.datablocks.structure.categories.atom_sites.enums import (  # noqa: PLC0415
+            AdpTypeEnum,
+        )
+
+        aniso_types = {AdpTypeEnum.BANI.value, AdpTypeEnum.UANI.value}
+        return not any(atom.adp_type.value in aniso_types for atom in atom_sites)
+
+    def _iso_labels(self) -> set[str]:
+        """Return labels of atoms with isotropic ADP type."""
+        structure = getattr(self, '_parent', None)
+        if structure is None:
+            return set()
+        atom_sites = getattr(structure, '_atom_sites', None)
+        if atom_sites is None:
+            return set()
+        from easydiffraction.datablocks.structure.categories.atom_sites.enums import (  # noqa: PLC0415
+            AdpTypeEnum,
+        )
+
+        iso_types = {AdpTypeEnum.BISO.value, AdpTypeEnum.UISO.value}
+        return {atom.label.value for atom in atom_sites if atom.adp_type.value in iso_types}
+
+    def _format_cif_row(self, item: object) -> list[str] | None:
+        """
+        Return ``?`` markers for isotropic atoms, ``None`` otherwise.
+
+        Used by :func:`category_collection_to_cif` as a per-row hook.
+        Atoms whose ADP type is isotropic get ``?`` for the six tensor
+        components so they are not mistaken for genuine zeros.
+
+        Parameters
+        ----------
+        item : object
+            An :class:`AtomSiteAniso` instance.
+
+        Returns
+        -------
+        list[str] | None
+            Formatted row when overridden, ``None`` for default output.
+        """
+        if item.label.value not in self._iso_labels():
+            return None
+        from easydiffraction.io.cif.serialize import format_param_value  # noqa: PLC0415
+        from easydiffraction.io.cif.serialize import format_value  # noqa: PLC0415
+
+        row = [format_param_value(item._label)]
+        row.extend([format_value(None)] * 6)
+        return row
diff --git a/src/easydiffraction/datablocks/structure/categories/atom_site_aniso/factory.py b/src/easydiffraction/datablocks/structure/categories/atom_site_aniso/factory.py
new file mode 100644
index 000000000..394c3211f
--- /dev/null
+++ b/src/easydiffraction/datablocks/structure/categories/atom_site_aniso/factory.py
@@ -0,0 +1,17 @@
+# SPDX-FileCopyrightText: 2026 EasyScience contributors <https://github.com/easyscience>
+# SPDX-License-Identifier: BSD-3-Clause
+"""Atom-site-aniso factory — delegates entirely to ``FactoryBase``."""
+
+from __future__ import annotations
+
+from typing import ClassVar
+
+from easydiffraction.core.factory import FactoryBase
+
+
+class AtomSiteAnisoFactory(FactoryBase):
+    """Create atom-site-aniso collections by tag."""
+
+    _default_rules: ClassVar[dict] = {
+        frozenset(): 'default',
+    }
diff --git a/src/easydiffraction/datablocks/structure/categories/atom_sites/__init__.py b/src/easydiffraction/datablocks/structure/categories/atom_sites/__init__.py
index 7bd7b9ad4..feb70b52b 100644
--- a/src/easydiffraction/datablocks/structure/categories/atom_sites/__init__.py
+++ b/src/easydiffraction/datablocks/structure/categories/atom_sites/__init__.py
@@ -3,3 +3,4 @@
 
 from easydiffraction.datablocks.structure.categories.atom_sites.default import AtomSite
 from easydiffraction.datablocks.structure.categories.atom_sites.default import AtomSites
+from easydiffraction.datablocks.structure.categories.atom_sites.enums import AdpTypeEnum
diff --git a/src/easydiffraction/datablocks/structure/categories/atom_sites/default.py b/src/easydiffraction/datablocks/structure/categories/atom_sites/default.py
index db528d968..7396e9538 100644
--- a/src/easydiffraction/datablocks/structure/categories/atom_sites/default.py
+++ b/src/easydiffraction/datablocks/structure/categories/atom_sites/default.py
@@ -9,6 +9,8 @@
 
 from __future__ import annotations
 
+import math
+
 from cryspy.A_functions_base.database import DATABASE
 
 from easydiffraction.core.category import CategoryCollection
@@ -21,6 +23,7 @@
 from easydiffraction.core.variable import Parameter
 from easydiffraction.core.variable import StringDescriptor
 from easydiffraction.crystallography import crystallography as ecr
+from easydiffraction.datablocks.structure.categories.atom_sites.enums import AdpTypeEnum
 from easydiffraction.datablocks.structure.categories.atom_sites.factory import AtomSitesFactory
 from easydiffraction.io.cif.handler import CifHandler
 
@@ -110,23 +113,28 @@ def __init__(self) -> None:
             ),
             cif_handler=CifHandler(names=['_atom_site.occupancy']),
         )
-        self._b_iso = Parameter(
-            name='b_iso',
+        self._adp_iso = Parameter(
+            name='adp_iso',
             description='Isotropic atomic displacement parameter (ADP) for the atom site.',
             units='Ų',
             value_spec=AttributeSpec(
                 default=0.0,
                 validator=RangeValidator(ge=0.0, le=100.0),
             ),
-            cif_handler=CifHandler(names=['_atom_site.B_iso_or_equiv']),
+            cif_handler=CifHandler(
+                names=[
+                    '_atom_site.B_iso_or_equiv',
+                    '_atom_site.U_iso_or_equiv',
+                ]
+            ),
         )
         self._adp_type = StringDescriptor(
             name='adp_type',
             description='Type of atomic displacement parameter (ADP) '
             'used (e.g., Biso, Uiso, Uani, Bani).',
             value_spec=AttributeSpec(
-                default='Biso',
-                validator=MembershipValidator(allowed=['Biso']),
+                default=AdpTypeEnum.default(),
+                validator=MembershipValidator(allowed=[m.value for m in AdpTypeEnum]),
             ),
             cif_handler=CifHandler(names=['_atom_site.adp_type']),
         )
@@ -179,6 +187,156 @@ def _wyckoff_letter_default_value(self) -> str:
         # TODO: What to pass as default?
         return self._wyckoff_letter_allowed_values[0]
 
+    def _convert_adp_values(self, old_type: str, new_type: str) -> None:
+        """
+        Convert ADP values when the type changes.
+
+        Handles B ↔ U conversion using B = 8π²U and iso ↔ ani seeding.
+
+        Parameters
+        ----------
+        old_type : str
+            Previous ADP type value.
+        new_type : str
+            New ADP type value.
+        """
+        old_enum = AdpTypeEnum(old_type)
+        new_enum = AdpTypeEnum(new_type)
+        factor = 8.0 * math.pi**2
+        old_is_b = old_enum in {AdpTypeEnum.BISO, AdpTypeEnum.BANI}
+        new_is_u = new_enum in {AdpTypeEnum.UISO, AdpTypeEnum.UANI}
+        old_is_iso = old_enum in {AdpTypeEnum.BISO, AdpTypeEnum.UISO}
+        new_is_iso = new_enum in {AdpTypeEnum.BISO, AdpTypeEnum.UISO}
+
+        # Ani → Iso: collapse tensor to scalar first (in old units)
+        if not old_is_iso and new_is_iso:
+            self._collapse_aniso_to_iso()
+
+        # B ↔ U conversion for iso value
+        if old_is_b and new_is_u:
+            self._adp_iso.value /= factor
+        elif not old_is_b and not new_is_u:
+            self._adp_iso.value *= factor
+
+        # Iso → Ani: seed diagonal from (already converted) adp_iso
+        if old_is_iso and not new_is_iso:
+            self._seed_aniso_from_iso()
+        elif not old_is_iso and not new_is_iso:
+            # Ani → Ani (e.g. Bani→Uani): apply B↔U to aniso values
+            aniso = self._get_aniso_entry()
+            if aniso is not None:
+                self._convert_aniso_values(
+                    aniso,
+                    old_is_b=old_is_b,
+                    new_is_u=new_is_u,
+                    factor=factor,
+                )
+
+    def _seed_aniso_from_iso(self) -> None:
+        """Seed aniso diagonal from current adp_iso value."""
+        aniso = self._get_aniso_entry()
+        if aniso is None:
+            # Entry not yet created; force sync on parent
+            structure = getattr(self._parent, '_parent', None)
+            if structure is not None and hasattr(structure, '_sync_atom_site_aniso'):
+                structure._sync_atom_site_aniso()
+                aniso = self._get_aniso_entry()
+        if aniso is None:
+            return
+        iso_val = self._adp_iso.value
+        aniso.adp_11 = iso_val
+        aniso.adp_22 = iso_val
+        aniso.adp_33 = iso_val
+        aniso.adp_12 = 0.0
+        aniso.adp_13 = 0.0
+        aniso.adp_23 = 0.0
+
+    def _collapse_aniso_to_iso(self) -> None:
+        """
+        Set adp_iso to the mean of the aniso diagonal.
+
+        Writes directly to ``_value`` to bypass range validation,
+        because intermediate minimizer steps can produce negative
+        anisotropic components whose mean falls outside the nominal
+        ``[0, 100]`` range.
+        """
+        aniso = self._get_aniso_entry()
+        if aniso is None:
+            return
+        self._adp_iso._value = (aniso.adp_11.value + aniso.adp_22.value + aniso.adp_33.value) / 3.0
+
+    def _get_aniso_entry(self) -> object | None:
+        """Return the matching AtomSiteAniso entry, or None."""
+        # _parent is absent before the atom is added to a collection
+        if '_parent' not in self.__dict__:
+            return None
+        structure = getattr(self._parent, '_parent', None)
+        if structure is None:
+            return None
+        aniso_coll = getattr(structure, '_atom_site_aniso', None)
+        if aniso_coll is None:
+            return None
+        lbl = self._label.value
+        if lbl in aniso_coll:
+            return aniso_coll[lbl]
+        return None
+
+    @staticmethod
+    def _convert_aniso_values(
+        aniso: object,
+        *,
+        old_is_b: bool,
+        new_is_u: bool,
+        factor: float,
+    ) -> None:
+        """Apply B↔U conversion to all six aniso tensor components."""
+        if old_is_b and new_is_u:
+            for attr in ('adp_11', 'adp_22', 'adp_33', 'adp_12', 'adp_13', 'adp_23'):
+                p = getattr(aniso, attr)
+                p.value /= factor
+        elif not old_is_b and not new_is_u:
+            for attr in ('adp_11', 'adp_22', 'adp_33', 'adp_12', 'adp_13', 'adp_23'):
+                p = getattr(aniso, attr)
+                p.value *= factor
+
+    def _reorder_adp_cif_names(self, new_type: str) -> None:
+        """
+        Reorder CIF names on adp_iso and aniso params for serialisation.
+
+        Parameters
+        ----------
+        new_type : str
+            The new ADP type value.
+        """
+        is_u = AdpTypeEnum(new_type) in {AdpTypeEnum.UISO, AdpTypeEnum.UANI}
+        if is_u:
+            self._adp_iso._cif_handler._names = [
+                '_atom_site.U_iso_or_equiv',
+                '_atom_site.B_iso_or_equiv',
+            ]
+        else:
+            self._adp_iso._cif_handler._names = [
+                '_atom_site.B_iso_or_equiv',
+                '_atom_site.U_iso_or_equiv',
+            ]
+
+        # Reorder aniso CIF names
+        aniso = self._get_aniso_entry()
+        if aniso is None:
+            return
+        for suffix in ('11', '22', '33', '12', '13', '23'):
+            param = getattr(aniso, f'_adp_{suffix}')
+            if is_u:
+                param._cif_handler._names = [
+                    f'_atom_site_aniso.U_{suffix}',
+                    f'_atom_site_aniso.B_{suffix}',
+                ]
+            else:
+                param._cif_handler._names = [
+                    f'_atom_site_aniso.B_{suffix}',
+                    f'_atom_site_aniso.U_{suffix}',
+                ]
+
     # ------------------------------------------------------------------
     #  Public properties
     # ------------------------------------------------------------------
@@ -226,7 +384,15 @@ def adp_type(self) -> StringDescriptor:
 
     @adp_type.setter
     def adp_type(self, value: str) -> None:
+        old_type = self._adp_type.value
         self._adp_type.value = value
+        new_type = self._adp_type.value
+        if old_type != new_type:
+            self._convert_adp_values(old_type, new_type)
+            self._reorder_adp_cif_names(new_type)
+            parent = getattr(self, '_parent', None)
+            if parent is not None:
+                parent._propagate_adp_convention(self)
 
     @property
     def wyckoff_letter(self) -> StringDescriptor:
@@ -300,18 +466,36 @@ def occupancy(self, value: float) -> None:
         self._occupancy.value = value
 
     @property
-    def b_iso(self) -> Parameter:
+    def adp_iso(self) -> Parameter:
         """
         Isotropic ADP for the atom site (Ų).
 
         Reading this property returns the underlying ``Parameter``
         object. Assigning to it updates the parameter value.
         """
-        return self._b_iso
+        return self._adp_iso
+
+    @adp_iso.setter
+    def adp_iso(self, value: float) -> None:
+        self._adp_iso.value = value
+
+    @property
+    def adp_iso_as_b(self) -> float:
+        """
+        Return the isotropic ADP as a B-factor value.
+
+        When ``adp_type`` is ``Uiso`` or ``Uani`` the stored U value is
+        converted to B via B = 8π²U.  Otherwise the stored value is
+        returned unchanged.
 
-    @b_iso.setter
-    def b_iso(self, value: float) -> None:
-        self._b_iso.value = value
+        Returns
+        -------
+        float
+            Equivalent B_iso value.
+        """
+        if AdpTypeEnum(self._adp_type.value) in {AdpTypeEnum.UISO, AdpTypeEnum.UANI}:
+            return self._adp_iso.value * 8.0 * math.pi**2
+        return self._adp_iso.value
 
 
 @AtomSitesFactory.register
@@ -331,6 +515,39 @@ def __init__(self) -> None:
     #  Private helper methods
     # ------------------------------------------------------------------
 
+    def _propagate_adp_convention(self, source: AtomSite) -> None:
+        """
+        Align all atoms to the B/U convention of *source*.
+
+        When an atom switches between B and U convention, all siblings
+        are converted to the same convention so that CIF loop headers
+        remain consistent.
+
+        Parameters
+        ----------
+        source : AtomSite
+            The atom whose convention just changed.
+        """
+        new_enum = AdpTypeEnum(source._adp_type.value)
+        target_is_u = new_enum in {AdpTypeEnum.UISO, AdpTypeEnum.UANI}
+
+        for atom in self._items:
+            if atom is source:
+                continue
+            sib_enum = AdpTypeEnum(atom._adp_type.value)
+            sib_is_u = sib_enum in {AdpTypeEnum.UISO, AdpTypeEnum.UANI}
+            if sib_is_u == target_is_u:
+                continue
+            sib_is_iso = sib_enum in {AdpTypeEnum.BISO, AdpTypeEnum.UISO}
+            if target_is_u:
+                target = AdpTypeEnum.UISO if sib_is_iso else AdpTypeEnum.UANI
+            else:
+                target = AdpTypeEnum.BISO if sib_is_iso else AdpTypeEnum.BANI
+            old_sib = atom._adp_type.value
+            atom._adp_type._value = target.value
+            atom._convert_adp_values(old_sib, target.value)
+            atom._reorder_adp_cif_names(target.value)
+
     def _apply_atomic_coordinates_symmetry_constraints(self) -> None:
         """
         Apply symmetry rules to fractional coordinates of every site.
@@ -362,6 +579,74 @@ def _apply_atomic_coordinates_symmetry_constraints(self) -> None:
             atom.fract_y.value = dummy_atom['fract_y']
             atom.fract_z.value = dummy_atom['fract_z']
 
+    def _apply_adp_symmetry_constraints(self) -> None:
+        """
+        Apply symmetry rules to anisotropic ADP tensor components.
+
+        For each atom with an anisotropic ADP type and a Wyckoff letter,
+        enforces the tensor constraints dictated by the site symmetry.
+        Also sets ``free = False`` on tensor components that are fixed
+        by symmetry and on ``adp_iso`` for all anisotropic atoms.
+        """
+        structure = self._parent
+        aniso_types = {AdpTypeEnum.BANI.value, AdpTypeEnum.UANI.value}
+        space_group_name = structure.space_group.name_h_m.value
+        space_group_coord_code = structure.space_group.it_coordinate_system_code.value
+        aniso_collection = structure.atom_site_aniso
+
+        for atom in self._items:
+            if atom.adp_type.value not in aniso_types:
+                continue
+            # Isotropic ADP is not refinable for aniso atoms
+            atom._adp_iso.free = False
+            wl = atom.wyckoff_letter.value
+            if not wl:
+                continue
+            lbl = atom.label.value
+            if lbl not in aniso_collection:
+                continue
+            aniso_entry = aniso_collection[lbl]
+            dummy = {
+                'adp_11': aniso_entry.adp_11.value,
+                'adp_22': aniso_entry.adp_22.value,
+                'adp_33': aniso_entry.adp_33.value,
+                'adp_12': aniso_entry.adp_12.value,
+                'adp_13': aniso_entry.adp_13.value,
+                'adp_23': aniso_entry.adp_23.value,
+            }
+            site_fract = (
+                atom.fract_x.value,
+                atom.fract_y.value,
+                atom.fract_z.value,
+            )
+            dummy, ref_i = ecr.apply_atom_site_aniso_symmetry_constraints(
+                atom_site_aniso=dummy,
+                name_hm=space_group_name,
+                coord_code=space_group_coord_code,
+                _wyckoff_letter=wl,
+                site_fract=site_fract,
+            )
+            adp_keys = ('adp_11', 'adp_22', 'adp_33', 'adp_12', 'adp_13', 'adp_23')
+            for key, is_free in zip(adp_keys, ref_i, strict=False):
+                param = getattr(aniso_entry, key)
+                param.value = dummy[key]
+                if not is_free:
+                    param.free = False
+
+    def _sync_iso_from_aniso(self) -> None:
+        """
+        Update ``adp_iso`` from the anisotropic tensor for aniso atoms.
+
+        For every atom whose ADP type is anisotropic (Bani / Uani), sets
+        ``adp_iso`` to the mean of the three diagonal tensor components
+        so that the isotropic value stays consistent with the current
+        tensor state.
+        """
+        aniso_types = {AdpTypeEnum.BANI.value, AdpTypeEnum.UANI.value}
+        for atom in self._items:
+            if atom.adp_type.value in aniso_types:
+                atom._collapse_aniso_to_iso()
+
     def _update(
         self,
         *,
@@ -379,3 +664,5 @@ def _update(
         del called_by_minimizer
 
         self._apply_atomic_coordinates_symmetry_constraints()
+        self._apply_adp_symmetry_constraints()
+        self._sync_iso_from_aniso()
diff --git a/src/easydiffraction/datablocks/structure/categories/atom_sites/enums.py b/src/easydiffraction/datablocks/structure/categories/atom_sites/enums.py
new file mode 100644
index 000000000..9ca3d3b57
--- /dev/null
+++ b/src/easydiffraction/datablocks/structure/categories/atom_sites/enums.py
@@ -0,0 +1,31 @@
+# SPDX-FileCopyrightText: 2026 EasyScience contributors <https://github.com/easyscience>
+# SPDX-License-Identifier: BSD-3-Clause
+"""Enumeration for ADP type values."""
+
+from __future__ import annotations
+
+from enum import StrEnum
+
+
+class AdpTypeEnum(StrEnum):
+    """Atomic displacement parameter type."""
+
+    BISO = 'Biso'
+    UISO = 'Uiso'
+    BANI = 'Bani'
+    UANI = 'Uani'
+
+    @classmethod
+    def default(cls) -> AdpTypeEnum:
+        """Return the default ADP type (BISO)."""
+        return cls.BISO
+
+    def description(self) -> str:
+        """Return a human-readable description of this ADP type."""
+        descriptions = {
+            AdpTypeEnum.BISO: 'Isotropic B-factor (Debye-Waller)',
+            AdpTypeEnum.UISO: 'Isotropic mean-square displacement',
+            AdpTypeEnum.BANI: 'Anisotropic B-factor tensor',
+            AdpTypeEnum.UANI: 'Anisotropic mean-square displacement tensor',
+        }
+        return descriptions[self]
diff --git a/src/easydiffraction/datablocks/structure/item/base.py b/src/easydiffraction/datablocks/structure/item/base.py
index 633e0b22a..b9c9c7a5f 100644
--- a/src/easydiffraction/datablocks/structure/item/base.py
+++ b/src/easydiffraction/datablocks/structure/item/base.py
@@ -5,6 +5,11 @@
 from typeguard import typechecked
 
 from easydiffraction.core.datablock import DatablockItem
+from easydiffraction.datablocks.structure.categories.atom_site_aniso import AtomSiteAnisoCollection
+from easydiffraction.datablocks.structure.categories.atom_site_aniso.default import AtomSiteAniso
+from easydiffraction.datablocks.structure.categories.atom_site_aniso.factory import (
+    AtomSiteAnisoFactory,
+)
 from easydiffraction.datablocks.structure.categories.atom_sites import AtomSites
 from easydiffraction.datablocks.structure.categories.atom_sites.factory import AtomSitesFactory
 from easydiffraction.datablocks.structure.categories.cell import Cell
@@ -31,6 +36,8 @@ def __init__(
         self._space_group = SpaceGroupFactory.create(self._space_group_type)
         self._atom_sites_type: str = AtomSitesFactory.default_tag()
         self._atom_sites = AtomSitesFactory.create(self._atom_sites_type)
+        self._atom_site_aniso_type: str = AtomSiteAnisoFactory.default_tag()
+        self._atom_site_aniso = AtomSiteAnisoFactory.create(self._atom_site_aniso_type)
         self._identity.datablock_entry_name = lambda: self.name
 
     # ------------------------------------------------------------------
@@ -128,6 +135,79 @@ def atom_sites(self, new: AtomSites) -> None:
         """
         self._atom_sites = new
 
+    # ------------------------------------------------------------------
+    #  Atom site aniso (read-only, single type)
+    # ------------------------------------------------------------------
+
+    @property
+    def atom_site_aniso(self) -> AtomSiteAnisoCollection:
+        """Anisotropic-ADP collection for this structure."""
+        return self._atom_site_aniso
+
+    @atom_site_aniso.setter
+    @typechecked
+    def atom_site_aniso(self, new: AtomSiteAnisoCollection) -> None:
+        """
+        Replace the anisotropic-ADP collection for this structure.
+
+        Parameters
+        ----------
+        new : AtomSiteAnisoCollection
+            New aniso collection.
+        """
+        self._atom_site_aniso = new
+
+    # ------------------------------------------------------------------
+    # Private methods
+    # ------------------------------------------------------------------
+
+    def _sync_atom_site_aniso(self) -> None:
+        """
+        Reconcile ``atom_site_aniso`` with ``atom_sites``.
+
+        Ensures every atom in ``atom_sites`` has a matching entry in
+        ``atom_site_aniso`` and removes stale entries whose label no
+        longer appears in ``atom_sites``.  Reorders CIF names on aniso
+        parameters to match each atom's ``adp_type``.
+        """
+        existing_labels = {a.label.value for a in self._atom_sites}
+        aniso_labels = {a.label.value for a in self._atom_site_aniso}
+
+        # Add missing entries
+        for atom in self._atom_sites:
+            lbl = atom.label.value
+            if lbl not in aniso_labels:
+                entry = AtomSiteAniso()
+                entry.label = lbl
+                self._atom_site_aniso.add(entry)
+
+        # Remove stale entries
+        stale = [
+            a.label.value for a in self._atom_site_aniso if a.label.value not in existing_labels
+        ]
+        for lbl in stale:
+            self._atom_site_aniso.remove(lbl)
+
+        # Reorder CIF names to match each atom's adp_type
+        for atom in self._atom_sites:
+            atom._reorder_adp_cif_names(atom.adp_type.value)
+
+    def _update_categories(
+        self,
+        *,
+        called_by_minimizer: bool = False,
+    ) -> None:
+        """Update categories with atom_site_aniso sync."""
+        if not called_by_minimizer and not self._need_categories_update:
+            return
+
+        self._sync_atom_site_aniso()
+
+        for category in self.categories:
+            category._update(called_by_minimizer=called_by_minimizer)
+
+        self._need_categories_update = False
+
     # ------------------------------------------------------------------
     # Public methods
     # ------------------------------------------------------------------
diff --git a/src/easydiffraction/io/cif/serialize.py b/src/easydiffraction/io/cif/serialize.py
index a55361a58..c6a00e2c9 100644
--- a/src/easydiffraction/io/cif/serialize.py
+++ b/src/easydiffraction/io/cif/serialize.py
@@ -36,7 +36,6 @@ def format_value(value: object) -> str:
     minimizer's     finite-difference Jacobian probes (typically ~1e-8
     relative)     survive the float→string→float round-trip through CIF.
     """
-    width = 12
     precision = 8
 
     # Converting
@@ -58,10 +57,10 @@ def format_value(value: object) -> str:
 
     # Format floats with given precision
     if isinstance(value, float):
-        return f'{value:>{width}.{precision}f}'
-    # Format strings right-aligned
+        return f'{value:.{precision}f}'
+    # Format strings as-is
     if isinstance(value, str):
-        return f'{value:>{width}s}'
+        return value
     # Everything else: fallback
     return str(value)
 
@@ -101,8 +100,10 @@ def format_param_value(param: object) -> str:
     str
         Formatted CIF value string.
     """
-    is_free = getattr(param, 'free', False)
-    is_constrained = getattr(param, 'constrained', False)
+    from easydiffraction.core.variable import Parameter  # noqa: PLC0415
+
+    is_free = param.free if isinstance(param, Parameter) else False
+    is_constrained = param.constrained if isinstance(param, Parameter) else False
     value = param.value  # type: ignore[attr-defined]
 
     if not is_free or is_constrained or not isinstance(value, (int, float)):
@@ -145,6 +146,46 @@ def category_item_to_cif(item: object) -> str:
     return '\n'.join(lines)
 
 
+def _validate_loop_tags(
+    item: object,
+    header_tags: list[str],
+) -> None:
+    """Log an error if any row tag disagrees with *header_tags*."""
+    for col, p in enumerate(item.parameters):
+        tag = p._cif_handler.names[0]  # type: ignore[attr-defined]
+        if tag != header_tags[col]:
+            log.error(
+                f'CIF tag mismatch in loop column {col}: '
+                f"header expects '{header_tags[col]}', "
+                f"row has '{tag}'",
+                exc_type=ValueError,
+            )
+
+
+def _emit_loop_rows(
+    items: list,
+    row_fn: object,
+    header_tags: list[str],
+    max_display: int | None,
+) -> list[str]:
+    """Build formatted rows, optionally truncated."""
+    lines: list[str] = []
+    if max_display is not None and len(items) > max_display:
+        half = max_display // 2
+        for item in items[:half]:
+            _validate_loop_tags(item, header_tags)
+            lines.append(' '.join(row_fn(item)))
+        lines.append('...')
+        for item in items[-half:]:
+            _validate_loop_tags(item, header_tags)
+            lines.append(' '.join(row_fn(item)))
+    else:
+        for item in items:
+            _validate_loop_tags(item, header_tags)
+            lines.append(' '.join(row_fn(item)))
+    return lines
+
+
 def category_collection_to_cif(
     collection: object,
     max_display: int | None = None,
@@ -171,33 +212,34 @@ def category_collection_to_cif(
     if not len(collection):
         return ''
 
+    # Allow collections to conditionally suppress CIF output
+    skip = getattr(collection, '_skip_cif_serialization', None)
+    if skip is not None and skip():
+        return ''
+
     lines: list[str] = []
 
-    # Header
+    # Header — use first item's CIF tag names as the canonical columns
     first_item = next(iter(collection.values()))
     lines.append('loop_')
+    header_tags: list[str] = []
     for p in first_item.parameters:
         tags = p._cif_handler.names  # type: ignore[attr-defined]
+        header_tags.append(tags[0])
         lines.append(tags[0])
 
-    # Rows
-    # Limit number of displayed rows if requested
-    if max_display is not None and len(collection) > max_display:
-        half_display = max_display // 2
-        for i in range(half_display):
-            item = list(collection.values())[i]
-            row_vals = [format_param_value(p) for p in item.parameters]
-            lines.append(' '.join(row_vals))
-        lines.append('...')
-        for i in range(-half_display, 0):
-            item = list(collection.values())[i]
-            row_vals = [format_param_value(p) for p in item.parameters]
-            lines.append(' '.join(row_vals))
-    # No limit
-    else:
-        for item in collection.values():
-            row_vals = [format_param_value(p) for p in item.parameters]
-            lines.append(' '.join(row_vals))
+    # Allow collections to customise per-item row formatting
+    row_hook = getattr(collection, '_format_cif_row', None)
+
+    def _row(item: object) -> list[str]:
+        if row_hook is not None:
+            override = row_hook(item)
+            if override is not None:
+                return override
+        return [format_param_value(p) for p in item.parameters]
+
+    items = list(collection.values())
+    lines.extend(_emit_loop_rows(items, _row, header_tags, max_display))
 
     return '\n'.join(lines)
 
diff --git a/src/easydiffraction/summary/summary.py b/src/easydiffraction/summary/summary.py
index ea46bc63e..dfe3cbcba 100644
--- a/src/easydiffraction/summary/summary.py
+++ b/src/easydiffraction/summary/summary.py
@@ -107,7 +107,7 @@ def show_crystallographic_data(self) -> None:
                     f'{site.fract_y.value:.5f}',
                     f'{site.fract_z.value:.5f}',
                     f'{site.occupancy.value:.5f}',
-                    f'{site.b_iso.value:.5f}',
+                    f'{site.adp_iso.value:.5f}',
                 ]
                 for site in model.atom_sites
             ]
diff --git a/src/easydiffraction/utils/utils.py b/src/easydiffraction/utils/utils.py
index 39ec94438..838868b63 100644
--- a/src/easydiffraction/utils/utils.py
+++ b/src/easydiffraction/utils/utils.py
@@ -73,7 +73,7 @@ def _fetch_data_index() -> dict:
     _validate_url(index_url)
 
     # macOS: sha256sum index.json
-    index_hash = 'sha256:af64483b9e0941af56d582b9d50285b8404e3d10a103d8696cddf3850ee2b660'
+    index_hash = 'sha256:b73db869debfe56ee776920644bfd28704885e8287ec7edb556e6ad7335cfe36'
     destination_dirname = 'easydiffraction'
     destination_fname = 'data-index.json'
     cache_dir = pooch.os_cache(destination_dirname)
diff --git a/tests/functional/test_adp_switching.py b/tests/functional/test_adp_switching.py
new file mode 100644
index 000000000..5715219ed
--- /dev/null
+++ b/tests/functional/test_adp_switching.py
@@ -0,0 +1,244 @@
+# SPDX-FileCopyrightText: 2026 EasyScience contributors <https://github.com/easyscience>
+# SPDX-License-Identifier: BSD-3-Clause
+"""Functional tests for ADP type switching workflows."""
+
+from __future__ import annotations
+
+import math
+
+import pytest
+
+from easydiffraction import Project
+
+_FACTOR = 8.0 * math.pi**2
+
+
+def _make_project_with_structure():
+    """Build a project with a simple cubic structure."""
+    Project._loading = True
+    try:
+        project = Project()
+    finally:
+        Project._loading = False
+    project.structures.create(name='cubic')
+    s = project.structures['cubic']
+    s.space_group.name_h_m = 'P m -3 m'
+    s.cell.length_a = 3.89
+    s.atom_sites.create(
+        label='A',
+        type_symbol='La',
+        fract_x=0,
+        fract_y=0,
+        fract_z=0,
+        wyckoff_letter='a',
+        adp_iso=0.5,
+    )
+    s.atom_sites.create(
+        label='B',
+        type_symbol='Co',
+        fract_x=0.5,
+        fract_y=0.5,
+        fract_z=0.5,
+        wyckoff_letter='b',
+        adp_iso=0.3,
+    )
+    return project
+
+
+# ------------------------------------------------------------------
+#  ADP type switching: value correctness
+# ------------------------------------------------------------------
+
+
+class TestAdpTypeSwitchingValues:
+    def test_biso_to_bani_preserves_value(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Bani'
+        aniso = s.atom_site_aniso['A']
+        assert aniso.adp_11.value == pytest.approx(0.5)
+        assert aniso.adp_22.value == pytest.approx(0.5)
+        assert aniso.adp_33.value == pytest.approx(0.5)
+        assert aniso.adp_12.value == pytest.approx(0.0)
+
+    def test_biso_to_uiso_converts(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Uiso'
+        expected = 0.5 / _FACTOR
+        assert s.atom_sites['A'].adp_iso.value == pytest.approx(expected)
+
+    def test_biso_to_uani_converts_and_seeds(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Uani'
+        aniso = s.atom_site_aniso['A']
+        expected = 0.5 / _FACTOR
+        assert aniso.adp_11.value == pytest.approx(expected)
+        assert aniso.adp_22.value == pytest.approx(expected)
+        assert aniso.adp_33.value == pytest.approx(expected)
+
+    def test_uiso_to_biso_converts(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Uiso'
+        u_val = s.atom_sites['A'].adp_iso.value
+        s.atom_sites['A'].adp_type = 'Biso'
+        assert s.atom_sites['A'].adp_iso.value == pytest.approx(u_val * _FACTOR)
+
+    def test_uani_to_bani_converts_tensor(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Uani'
+        u11 = s.atom_site_aniso['A'].adp_11.value
+        s.atom_sites['A'].adp_type = 'Bani'
+        b11 = s.atom_site_aniso['A'].adp_11.value
+        assert b11 == pytest.approx(u11 * _FACTOR)
+
+    def test_bani_to_uani_converts_tensor(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Bani'
+        b11 = s.atom_site_aniso['A'].adp_11.value
+        s.atom_sites['A'].adp_type = 'Uani'
+        u11 = s.atom_site_aniso['A'].adp_11.value
+        assert u11 == pytest.approx(b11 / _FACTOR)
+
+
+# ------------------------------------------------------------------
+#  Round trips
+# ------------------------------------------------------------------
+
+
+class TestAdpRoundTrips:
+    def test_biso_bani_biso(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Bani'
+        s.atom_sites['A'].adp_type = 'Biso'
+        assert s.atom_sites['A'].adp_iso.value == pytest.approx(0.5)
+
+    def test_biso_uani_biso(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Uani'
+        s.atom_sites['A'].adp_type = 'Biso'
+        assert s.atom_sites['A'].adp_iso.value == pytest.approx(0.5)
+
+    def test_uiso_uani_uiso(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Uiso'
+        u_val = s.atom_sites['A'].adp_iso.value
+        s.atom_sites['A'].adp_type = 'Uani'
+        s.atom_sites['A'].adp_type = 'Uiso'
+        assert s.atom_sites['A'].adp_iso.value == pytest.approx(u_val)
+
+    def test_biso_uiso_biso(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Uiso'
+        s.atom_sites['A'].adp_type = 'Biso'
+        assert s.atom_sites['A'].adp_iso.value == pytest.approx(0.5)
+
+    def test_full_cycle_biso_uiso_uani_bani_biso(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Uiso'
+        s.atom_sites['A'].adp_type = 'Uani'
+        s.atom_sites['A'].adp_type = 'Bani'
+        s.atom_sites['A'].adp_type = 'Biso'
+        assert s.atom_sites['A'].adp_iso.value == pytest.approx(0.5)
+
+
+# ------------------------------------------------------------------
+#  Mixed ADP types in the same structure
+# ------------------------------------------------------------------
+
+
+class TestMixedAdpTypes:
+    def test_mixed_types_coexist(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Uani'  # Auto-changed to Bani by next line
+        s.atom_sites['B'].adp_type = 'Biso'
+        assert s.atom_sites['A'].adp_type.value == 'Bani'
+        assert s.atom_sites['B'].adp_type.value == 'Biso'
+
+    def test_mixed_cif_has_question_marks_for_iso(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Bani'
+        cif = s.atom_site_aniso.as_cif
+        # A is Bani → numerical values
+        # B is Biso → ? markers
+        lines = cif.strip().split('\n')
+        data_lines = [l for l in lines if not l.startswith(('loop_', '_atom_site_aniso'))]
+        b_line = next(l for l in data_lines if 'B ' in l or l.startswith('B '))
+        assert '?' in b_line
+
+    def test_all_iso_suppresses_aniso_cif(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        cif = s.atom_site_aniso.as_cif
+        assert cif == ''
+
+    def test_adp_iso_syncs_from_aniso_on_update(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Bani'
+        # In P m -3 m, Wyckoff 'a' constrains U11=U22=U33, U12=U13=U23=0
+        # so any set of diagonal values collapses to U11 after update
+        s.atom_site_aniso['A'].adp_11 = 0.3
+        s.atom_site_aniso['A'].adp_22 = 0.6
+        s.atom_site_aniso['A'].adp_33 = 0.9
+        s._update_categories()
+        # After symmetry constraints: all diags = 0.3 (first value wins)
+        aniso = s.atom_site_aniso['A']
+        assert aniso.adp_11.value == pytest.approx(aniso.adp_22.value)
+        assert aniso.adp_11.value == pytest.approx(aniso.adp_33.value)
+        # adp_iso should match the constrained diagonal mean
+        expected = (aniso.adp_11.value + aniso.adp_22.value + aniso.adp_33.value) / 3.0
+        assert s.atom_sites['A'].adp_iso.value == pytest.approx(expected)
+
+    def test_adp_iso_unchanged_for_iso_atom_on_update(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Bani'
+        s._update_categories()
+        # B stays Biso → its adp_iso should not change
+        assert s.atom_sites['B'].adp_iso.value == pytest.approx(0.3)
+
+
+# ------------------------------------------------------------------
+#  CIF name selection based on ADP type
+# ------------------------------------------------------------------
+
+
+class TestCifNamesByAdpType:
+    def test_biso_uses_b_names(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        site = s.atom_sites['A']
+        assert '_atom_site.B_iso_or_equiv' in site._adp_iso._cif_handler.names[0]
+
+    def test_uiso_uses_u_names(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Uiso'
+        site = s.atom_sites['A']
+        assert '_atom_site.U_iso_or_equiv' in site._adp_iso._cif_handler.names[0]
+
+    def test_bani_uses_b_aniso_names(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Bani'
+        aniso = s.atom_site_aniso['A']
+        assert aniso._adp_11._cif_handler.names[0] == '_atom_site_aniso.B_11'
+
+    def test_uani_uses_u_aniso_names(self):
+        project = _make_project_with_structure()
+        s = project.structures['cubic']
+        s.atom_sites['A'].adp_type = 'Uani'
+        aniso = s.atom_site_aniso['A']
+        assert aniso._adp_11._cif_handler.names[0] == '_atom_site_aniso.U_11'
diff --git a/tests/functional/test_experiment_workflow.py b/tests/functional/test_experiment_workflow.py
index ffc3da25b..9fd1ef617 100644
--- a/tests/functional/test_experiment_workflow.py
+++ b/tests/functional/test_experiment_workflow.py
@@ -34,7 +34,7 @@ def _make_project_with_experiment():
         fract_z=0,
         wyckoff_letter='a',
         occupancy=0.5,
-        b_iso=0.5,
+        adp_iso=0.5,
     )
 
     # Add experiment from data file
diff --git a/tests/functional/test_fitting_workflow.py b/tests/functional/test_fitting_workflow.py
index 9250bd9d9..3fde95dde 100644
--- a/tests/functional/test_fitting_workflow.py
+++ b/tests/functional/test_fitting_workflow.py
@@ -35,7 +35,7 @@ def _make_fit_ready_project():
         fract_z=0,
         wyckoff_letter='a',
         occupancy=0.5,
-        b_iso=0.5,
+        adp_iso=0.5,
     )
     s.atom_sites.create(
         label='Ba',
@@ -45,7 +45,7 @@ def _make_fit_ready_project():
         fract_z=0,
         wyckoff_letter='a',
         occupancy=0.5,
-        b_iso=0.5,
+        adp_iso=0.5,
     )
     s.atom_sites.create(
         label='Co',
@@ -54,7 +54,7 @@ def _make_fit_ready_project():
         fract_y=0.5,
         fract_z=0.5,
         wyckoff_letter='b',
-        b_iso=0.5,
+        adp_iso=0.5,
     )
     s.atom_sites.create(
         label='O',
@@ -63,7 +63,7 @@ def _make_fit_ready_project():
         fract_y=0.5,
         fract_z=0.5,
         wyckoff_letter='c',
-        b_iso=0.5,
+        adp_iso=0.5,
     )
 
     # Experiment
@@ -100,7 +100,7 @@ def test_create_alias(self):
         s = project.structures['lbco']
         project.analysis.aliases.create(
             label='biso_La',
-            param=s.atom_sites['La'].b_iso,
+            param=s.atom_sites['La'].adp_iso,
         )
         assert len(project.analysis.aliases) == 1
 
@@ -109,11 +109,11 @@ def test_create_multiple_aliases(self):
         s = project.structures['lbco']
         project.analysis.aliases.create(
             label='biso_La',
-            param=s.atom_sites['La'].b_iso,
+            param=s.atom_sites['La'].adp_iso,
         )
         project.analysis.aliases.create(
             label='biso_Ba',
-            param=s.atom_sites['Ba'].b_iso,
+            param=s.atom_sites['Ba'].adp_iso,
         )
         assert len(project.analysis.aliases) == 2
 
@@ -124,11 +124,11 @@ def test_create_constraint(self):
         s = project.structures['lbco']
         project.analysis.aliases.create(
             label='biso_La',
-            param=s.atom_sites['La'].b_iso,
+            param=s.atom_sites['La'].adp_iso,
         )
         project.analysis.aliases.create(
             label='biso_Ba',
-            param=s.atom_sites['Ba'].b_iso,
+            param=s.atom_sites['Ba'].adp_iso,
         )
         project.analysis.constraints.create(
             expression='biso_Ba = biso_La',
@@ -162,16 +162,16 @@ def test_fit_updates_parameter_values(self):
     def test_fit_with_constraints(self):
         project = _make_fit_ready_project()
         s = project.structures['lbco']
-        s.atom_sites['La'].b_iso.free = True
-        s.atom_sites['Ba'].b_iso.free = True
+        s.atom_sites['La'].adp_iso.free = True
+        s.atom_sites['Ba'].adp_iso.free = True
 
         project.analysis.aliases.create(
             label='biso_La',
-            param=s.atom_sites['La'].b_iso,
+            param=s.atom_sites['La'].adp_iso,
         )
         project.analysis.aliases.create(
             label='biso_Ba',
-            param=s.atom_sites['Ba'].b_iso,
+            param=s.atom_sites['Ba'].adp_iso,
         )
         project.analysis.constraints.create(
             expression='biso_Ba = biso_La',
@@ -180,6 +180,6 @@ def test_fit_with_constraints(self):
         project.analysis.fit(verbosity='silent')
         assert project.analysis.fit_results.success is True
         # Constrained params should be equal after fitting
-        la_biso = s.atom_sites['La'].b_iso.value
-        ba_biso = s.atom_sites['Ba'].b_iso.value
+        la_biso = s.atom_sites['La'].adp_iso.value
+        ba_biso = s.atom_sites['Ba'].adp_iso.value
         assert la_biso == pytest.approx(ba_biso, rel=1e-3)
diff --git a/tests/functional/test_structure_workflow.py b/tests/functional/test_structure_workflow.py
index 4ed2da3f6..23ac232e6 100644
--- a/tests/functional/test_structure_workflow.py
+++ b/tests/functional/test_structure_workflow.py
@@ -77,7 +77,7 @@ def test_create_atom_site(self):
             fract_y=0,
             fract_z=0,
             wyckoff_letter='a',
-            b_iso=0.5,
+            adp_iso=0.5,
         )
         assert len(s.atom_sites) == 1
 
@@ -92,11 +92,11 @@ def test_access_atom_site_by_label(self):
             fract_y=0,
             fract_z=0,
             wyckoff_letter='a',
-            b_iso=0.5,
+            adp_iso=0.5,
         )
         atom = s.atom_sites['La']
         assert atom.fract_x.value == pytest.approx(0)
-        assert atom.b_iso.value == pytest.approx(0.5)
+        assert atom.adp_iso.value == pytest.approx(0.5)
 
     def test_atom_site_fract_is_fittable(self):
         project = _make_project()
@@ -109,7 +109,7 @@ def test_atom_site_fract_is_fittable(self):
             fract_y=0.2,
             fract_z=0.3,
             wyckoff_letter='a',
-            b_iso=0.5,
+            adp_iso=0.5,
         )
         s.atom_sites['La'].fract_x.free = True
         assert s.atom_sites['La'].fract_x.free is True
@@ -125,7 +125,7 @@ def test_multiple_atom_sites(self):
             fract_y=0,
             fract_z=0,
             wyckoff_letter='a',
-            b_iso=0.5,
+            adp_iso=0.5,
         )
         s.atom_sites.create(
             label='O',
@@ -134,6 +134,6 @@ def test_multiple_atom_sites(self):
             fract_y=0.5,
             fract_z=0,
             wyckoff_letter='c',
-            b_iso=0.3,
+            adp_iso=0.3,
         )
         assert len(s.atom_sites) == 2
diff --git a/tests/integration/fitting/conftest.py b/tests/integration/fitting/conftest.py
index 83be2e17d..851576140 100644
--- a/tests/integration/fitting/conftest.py
+++ b/tests/integration/fitting/conftest.py
@@ -29,7 +29,7 @@ def lbco_fitted_project():
         fract_z=0,
         wyckoff_letter='a',
         occupancy=0.5,
-        b_iso=0.1,
+        adp_iso=0.1,
     )
     model.atom_sites.create(
         label='Ba',
@@ -39,7 +39,7 @@ def lbco_fitted_project():
         fract_z=0,
         wyckoff_letter='a',
         occupancy=0.5,
-        b_iso=0.1,
+        adp_iso=0.1,
     )
     model.atom_sites.create(
         label='Co',
@@ -48,7 +48,7 @@ def lbco_fitted_project():
         fract_y=0.5,
         fract_z=0.5,
         wyckoff_letter='b',
-        b_iso=0.1,
+        adp_iso=0.1,
     )
     model.atom_sites.create(
         label='O',
@@ -57,7 +57,7 @@ def lbco_fitted_project():
         fract_y=0.5,
         fract_z=0.5,
         wyckoff_letter='c',
-        b_iso=0.1,
+        adp_iso=0.1,
     )
 
     data_path = download_data(id=3, destination=TEMP_DIR)
diff --git a/tests/integration/fitting/test_aniso_adp_fitting.py b/tests/integration/fitting/test_aniso_adp_fitting.py
new file mode 100644
index 000000000..8daa6350a
--- /dev/null
+++ b/tests/integration/fitting/test_aniso_adp_fitting.py
@@ -0,0 +1,106 @@
+# SPDX-FileCopyrightText: 2026 EasyScience contributors <https://github.com/easyscience>
+# SPDX-License-Identifier: BSD-3-Clause
+"""Integration tests for anisotropic ADP fitting (Tb2Ti2O7, HEiDi)."""
+
+import tempfile
+
+import pytest
+
+import easydiffraction as ed
+
+TEMP_DIR = tempfile.gettempdir()
+
+
+def _setup_tbti_project():
+    """Create a Tb2Ti2O7 single-crystal project ready for fitting."""
+    project = ed.Project()
+
+    model_path = ed.download_data(id=20, destination=TEMP_DIR)
+    project.structures.add_from_cif_path(model_path)
+
+    data_path = ed.download_data(id=19, destination=TEMP_DIR)
+    project.experiments.add_from_data_path(
+        name='heidi',
+        data_path=data_path,
+        sample_form='single crystal',
+        beam_mode='constant wavelength',
+        radiation_probe='neutron',
+    )
+    experiment = project.experiments['heidi']
+    experiment.linked_crystal.id = 'tbti'
+    experiment.linked_crystal.scale = 1.0
+    experiment.instrument.setup_wavelength = 0.793
+    experiment.extinction.mosaicity = 35000
+    experiment.extinction.radius = 10
+
+    return project
+
+
+@pytest.mark.fast
+def test_iso_then_aniso_fit() -> None:
+    """Fit Uiso first, then switch to Uani and fit again."""
+    project = _setup_tbti_project()
+    s = project.structures['tbti']
+    e = project.experiments['heidi']
+
+    # Step 1: Set all atoms to Uiso with zero starting values
+    for name in ('Tb', 'Ti', 'O1', 'O2'):
+        s.atom_sites[name].adp_type = 'Uiso'
+        s.atom_sites[name].adp_iso = 0.0
+
+    # Free parameters for isotropic fit
+    s.atom_sites['O1'].fract_x.free = True
+    s.atom_sites['Ti'].occupancy.free = True
+    s.atom_sites['O1'].occupancy.free = True
+    s.atom_sites['O2'].occupancy.free = True
+    for name in ('Tb', 'Ti', 'O1', 'O2'):
+        s.atom_sites[name].adp_iso.free = True
+    e.linked_crystal.scale.free = True
+    e.extinction.radius.free = True
+
+    # Fit isotropic
+    project.analysis.fit(verbosity='silent')
+    chi2_iso = project.analysis.fit_results.reduced_chi_square
+    assert chi2_iso < 20.0
+
+    # Record iso values
+    u_iso_tb = s.atom_sites['Tb'].adp_iso.value
+    assert u_iso_tb > 0.0
+
+    # Step 2: Switch Tb, Ti, O1 to Uani (O2 stays Uiso)
+    for name in ('Tb', 'Ti', 'O1'):
+        s.atom_sites[name].adp_type = 'Uani'
+
+    # Free anisotropic parameters
+    s.atom_site_aniso['Tb'].adp_11.free = True
+    s.atom_site_aniso['Tb'].adp_12.free = True
+    s.atom_site_aniso['Ti'].adp_11.free = True
+    s.atom_site_aniso['Ti'].adp_12.free = True
+    s.atom_site_aniso['O1'].adp_11.free = True
+    s.atom_site_aniso['O1'].adp_22.free = True
+    s.atom_site_aniso['O1'].adp_23.free = True
+
+    # Fit anisotropic
+    project.analysis.fit(verbosity='silent')
+    chi2_aniso = project.analysis.fit_results.reduced_chi_square
+
+    # Anisotropic fit should improve (or at least match) chi2
+    assert chi2_aniso < chi2_iso + 1.0
+    assert chi2_aniso < 10.0
+
+    # Aniso tensor should have non-zero off-diagonal for Tb
+    assert abs(s.atom_site_aniso['Tb'].adp_12.value) > 0.0001
+
+    # O2 should still be Uiso
+    assert s.atom_sites['O2'].adp_type.value == 'Uiso'
+
+    # CIF should show ? for O2 in aniso loop
+    cif = s.atom_site_aniso.as_cif
+    lines = cif.strip().split('\n')
+    o2_lines = [l for l in lines if l.strip().startswith('O2')]
+    assert len(o2_lines) == 1
+    assert '?' in o2_lines[0]
+
+
+if __name__ == '__main__':
+    test_iso_then_aniso_fit()
diff --git a/tests/integration/fitting/test_cif_round_trip.py b/tests/integration/fitting/test_cif_round_trip.py
index 4ff5c02d1..17a5bff81 100644
--- a/tests/integration/fitting/test_cif_round_trip.py
+++ b/tests/integration/fitting/test_cif_round_trip.py
@@ -265,7 +265,7 @@ def test_structure_cif_round_trip_preserves_parameters() -> None:
         fract_z=0,
         wyckoff_letter='a',
         occupancy=0.5,
-        b_iso=0.5,
+        adp_iso=0.5,
     )
     original.atom_sites.create(
         label='Co',
@@ -274,7 +274,7 @@ def test_structure_cif_round_trip_preserves_parameters() -> None:
         fract_y=0.5,
         fract_z=0.5,
         wyckoff_letter='b',
-        b_iso=0.5,
+        adp_iso=0.5,
     )
     original.atom_sites.create(
         label='O',
@@ -283,7 +283,7 @@ def test_structure_cif_round_trip_preserves_parameters() -> None:
         fract_y=0.5,
         fract_z=0.5,
         wyckoff_letter='c',
-        b_iso=0.5,
+        adp_iso=0.5,
     )
     # Apply symmetry constraints before serialisation
     original._update_categories()
@@ -315,8 +315,8 @@ def test_structure_cif_round_trip_preserves_parameters() -> None:
             err_msg=f'fract_x mismatch for {label}',
         )
         assert_almost_equal(
-            loaded_site.b_iso.value,
-            orig_site.b_iso.value,
+            loaded_site.adp_iso.value,
+            orig_site.adp_iso.value,
             decimal=4,
-            err_msg=f'b_iso mismatch for {label}',
+            err_msg=f'adp_iso mismatch for {label}',
         )
diff --git a/tests/integration/fitting/test_multi.py b/tests/integration/fitting/test_multi.py
index f33d0bc4f..b25840f50 100644
--- a/tests/integration/fitting/test_multi.py
+++ b/tests/integration/fitting/test_multi.py
@@ -27,7 +27,7 @@ def test_single_fit_neutron_pd_tof_mcstas_lbco_si() -> None:
         fract_y=0,
         fract_z=0,
         wyckoff_letter='a',
-        b_iso=0.2,
+        adp_iso=0.2,
         occupancy=0.5,
     )
     model_1.atom_sites.create(
@@ -37,7 +37,7 @@ def test_single_fit_neutron_pd_tof_mcstas_lbco_si() -> None:
         fract_y=0,
         fract_z=0,
         wyckoff_letter='a',
-        b_iso=0.2,
+        adp_iso=0.2,
         occupancy=0.5,
     )
     model_1.atom_sites.create(
@@ -47,7 +47,7 @@ def test_single_fit_neutron_pd_tof_mcstas_lbco_si() -> None:
         fract_y=0.5,
         fract_z=0.5,
         wyckoff_letter='b',
-        b_iso=0.2567,
+        adp_iso=0.2567,
     )
     model_1.atom_sites.create(
         label='O',
@@ -56,7 +56,7 @@ def test_single_fit_neutron_pd_tof_mcstas_lbco_si() -> None:
         fract_y=0.5,
         fract_z=0.5,
         wyckoff_letter='c',
-        b_iso=1.4041,
+        adp_iso=1.4041,
     )
 
     model_2 = StructureFactory.from_scratch(name='si')
@@ -70,7 +70,7 @@ def test_single_fit_neutron_pd_tof_mcstas_lbco_si() -> None:
         fract_y=0.0,
         fract_z=0.0,
         wyckoff_letter='a',
-        b_iso=0.0,
+        adp_iso=0.0,
     )
 
     # Set experiment
@@ -111,12 +111,12 @@ def test_single_fit_neutron_pd_tof_mcstas_lbco_si() -> None:
 
     # Select fitting parameters
     model_1.cell.length_a.free = True
-    model_1.atom_sites['La'].b_iso.free = True
-    model_1.atom_sites['Ba'].b_iso.free = True
-    model_1.atom_sites['Co'].b_iso.free = True
-    model_1.atom_sites['O'].b_iso.free = True
+    model_1.atom_sites['La'].adp_iso.free = True
+    model_1.atom_sites['Ba'].adp_iso.free = True
+    model_1.atom_sites['Co'].adp_iso.free = True
+    model_1.atom_sites['O'].adp_iso.free = True
     model_2.cell.length_a.free = True
-    model_2.atom_sites['Si'].b_iso.free = True
+    model_2.atom_sites['Si'].adp_iso.free = True
     expt.linked_phases['lbco'].scale.free = True
     expt.linked_phases['si'].scale.free = True
     expt.peak.broad_gauss_sigma_0.free = True
@@ -151,7 +151,7 @@ def _test_joint_fit_bragg_pdf_neutron_pd_tof_si() -> None:
         fract_x=0.125,
         fract_y=0.125,
         fract_z=0.125,
-        b_iso=0.5,
+        adp_iso=0.5,
     )
 
     # Set Bragg experiment (SEPD, TOF)
@@ -205,7 +205,7 @@ def _test_joint_fit_bragg_pdf_neutron_pd_tof_si() -> None:
 
     # Select fitting parameters — shared structure
     model.cell.length_a.free = True
-    model.atom_sites['Si'].b_iso.free = True
+    model.atom_sites['Si'].adp_iso.free = True
 
     # Select fitting parameters — Bragg experiment
     bragg_expt.linked_phases['si'].scale.free = True
diff --git a/tests/integration/fitting/test_pair-distribution-function.py b/tests/integration/fitting/test_pair-distribution-function.py
index 066e727e5..3d3c4b97e 100644
--- a/tests/integration/fitting/test_pair-distribution-function.py
+++ b/tests/integration/fitting/test_pair-distribution-function.py
@@ -27,7 +27,7 @@ def test_single_fit_pdf_xray_pd_cw_nacl() -> None:
         fract_y=0,
         fract_z=0,
         wyckoff_letter='a',
-        b_iso=1.1053,
+        adp_iso=1.1053,
     )
     structure.atom_sites.create(
         label='Cl',
@@ -36,7 +36,7 @@ def test_single_fit_pdf_xray_pd_cw_nacl() -> None:
         fract_y=0.5,
         fract_z=0.5,
         wyckoff_letter='b',
-        b_iso=0.5708,
+        adp_iso=0.5708,
     )
 
     # Set experiment
@@ -61,8 +61,8 @@ def test_single_fit_pdf_xray_pd_cw_nacl() -> None:
 
     # Select fitting parameters
     structure.cell.length_a.free = True
-    structure.atom_sites['Na'].b_iso.free = True
-    structure.atom_sites['Cl'].b_iso.free = True
+    structure.atom_sites['Na'].adp_iso.free = True
+    structure.atom_sites['Cl'].adp_iso.free = True
     experiment.linked_phases['nacl'].scale.free = True
     experiment.peak.damp_q.free = True
     experiment.peak.sharp_delta_2.free = True
@@ -92,7 +92,7 @@ def test_single_fit_pdf_neutron_pd_cw_ni():
         fract_y=0,
         fract_z=0,
         wyckoff_letter='a',
-        b_iso=0.4281,
+        adp_iso=0.4281,
     )
 
     # Set experiment
@@ -116,7 +116,7 @@ def test_single_fit_pdf_neutron_pd_cw_ni():
 
     # Select fitting parameters
     structure.cell.length_a.free = True
-    structure.atom_sites['Ni'].b_iso.free = True
+    structure.atom_sites['Ni'].adp_iso.free = True
     experiment.linked_phases['ni'].scale.free = True
     experiment.peak.broad_q.free = True
     experiment.peak.sharp_delta_2.free = True
@@ -145,7 +145,7 @@ def test_single_fit_pdf_neutron_pd_tof_si():
         fract_y=0,
         fract_z=0,
         wyckoff_letter='a',
-        b_iso=0.717,
+        adp_iso=0.717,
     )
 
     # Set experiment
@@ -169,7 +169,7 @@ def test_single_fit_pdf_neutron_pd_tof_si():
 
     # Select fitting parameters
     project.structures['si'].cell.length_a.free = True
-    project.structures['si'].atom_sites['Si'].b_iso.free = True
+    project.structures['si'].atom_sites['Si'].adp_iso.free = True
     experiment.linked_phases['si'].scale.free = True
     experiment.peak.damp_q.free = True
     experiment.peak.broad_q.free = True
diff --git a/tests/integration/fitting/test_powder-diffraction_constant-wavelength.py b/tests/integration/fitting/test_powder-diffraction_constant-wavelength.py
index f81d1b756..a00e63b08 100644
--- a/tests/integration/fitting/test_powder-diffraction_constant-wavelength.py
+++ b/tests/integration/fitting/test_powder-diffraction_constant-wavelength.py
@@ -27,7 +27,7 @@ def test_single_fit_neutron_pd_cwl_lbco() -> None:
         fract_z=0,
         wyckoff_letter='a',
         occupancy=0.5,
-        b_iso=0.1,
+        adp_iso=0.1,
     )
     model.atom_sites.create(
         label='Ba',
@@ -37,7 +37,7 @@ def test_single_fit_neutron_pd_cwl_lbco() -> None:
         fract_z=0,
         wyckoff_letter='a',
         occupancy=0.5,
-        b_iso=0.1,
+        adp_iso=0.1,
     )
     model.atom_sites.create(
         label='Co',
@@ -46,7 +46,7 @@ def test_single_fit_neutron_pd_cwl_lbco() -> None:
         fract_y=0.5,
         fract_z=0.5,
         wyckoff_letter='b',
-        b_iso=0.1,
+        adp_iso=0.1,
     )
     model.atom_sites.create(
         label='O',
@@ -55,7 +55,7 @@ def test_single_fit_neutron_pd_cwl_lbco() -> None:
         fract_y=0.5,
         fract_z=0.5,
         wyckoff_letter='c',
-        b_iso=0.1,
+        adp_iso=0.1,
     )
 
     # Set experiment
@@ -128,10 +128,10 @@ def test_single_fit_neutron_pd_cwl_lbco() -> None:
     # ------------ 3rd fitting ------------
 
     # Select fitting parameters
-    model.atom_sites['La'].b_iso.free = True
-    model.atom_sites['Ba'].b_iso.free = True
-    model.atom_sites['Co'].b_iso.free = True
-    model.atom_sites['O'].b_iso.free = True
+    model.atom_sites['La'].adp_iso.free = True
+    model.atom_sites['Ba'].adp_iso.free = True
+    model.atom_sites['Co'].adp_iso.free = True
+    model.atom_sites['O'].adp_iso.free = True
 
     # Perform fit
     project.analysis.fit()
@@ -163,7 +163,7 @@ def test_single_fit_neutron_pd_cwl_lbco_with_constraints() -> None:
         fract_y=0,
         fract_z=0,
         wyckoff_letter='a',
-        b_iso=1.0,
+        adp_iso=1.0,
         occupancy=0.5,
     )
     atom_sites.create(
@@ -173,7 +173,7 @@ def test_single_fit_neutron_pd_cwl_lbco_with_constraints() -> None:
         fract_y=0,
         fract_z=0,
         wyckoff_letter='a',
-        b_iso=1.0,
+        adp_iso=1.0,
         occupancy=0.5,
     )
     atom_sites.create(
@@ -183,7 +183,7 @@ def test_single_fit_neutron_pd_cwl_lbco_with_constraints() -> None:
         fract_y=0.5,
         fract_z=0.5,
         wyckoff_letter='b',
-        b_iso=1.0,
+        adp_iso=1.0,
     )
     atom_sites.create(
         label='O',
@@ -192,7 +192,7 @@ def test_single_fit_neutron_pd_cwl_lbco_with_constraints() -> None:
         fract_y=0.5,
         fract_z=0.5,
         wyckoff_letter='c',
-        b_iso=1.0,
+        adp_iso=1.0,
     )
 
     # Set experiment
@@ -241,16 +241,16 @@ def test_single_fit_neutron_pd_cwl_lbco_with_constraints() -> None:
     # Select fitting parameters
     atom_sites['La'].occupancy.free = True
     atom_sites['Ba'].occupancy.free = True
-    atom_sites['La'].b_iso.free = True
-    atom_sites['Ba'].b_iso.free = True
-    atom_sites['Co'].b_iso.free = True
-    atom_sites['O'].b_iso.free = True
+    atom_sites['La'].adp_iso.free = True
+    atom_sites['Ba'].adp_iso.free = True
+    atom_sites['Co'].adp_iso.free = True
+    atom_sites['O'].adp_iso.free = True
 
     # Compare parameter values before fit
-    assert_almost_equal(atom_sites['La'].b_iso.value, 1.0, decimal=2)
-    assert_almost_equal(atom_sites['Ba'].b_iso.value, 1.0, decimal=2)
-    assert_almost_equal(atom_sites['Co'].b_iso.value, 1.0, decimal=2)
-    assert_almost_equal(atom_sites['O'].b_iso.value, 1.0, decimal=2)
+    assert_almost_equal(atom_sites['La'].adp_iso.value, 1.0, decimal=2)
+    assert_almost_equal(atom_sites['Ba'].adp_iso.value, 1.0, decimal=2)
+    assert_almost_equal(atom_sites['Co'].adp_iso.value, 1.0, decimal=2)
+    assert_almost_equal(atom_sites['O'].adp_iso.value, 1.0, decimal=2)
     assert_almost_equal(atom_sites['La'].occupancy.value, 0.5, decimal=2)
     assert_almost_equal(atom_sites['Ba'].occupancy.value, 0.5, decimal=2)
 
@@ -258,10 +258,10 @@ def test_single_fit_neutron_pd_cwl_lbco_with_constraints() -> None:
     project.analysis.fit()
 
     # Compare parameter values after fit
-    assert_almost_equal(atom_sites['La'].b_iso.value, desired=15.0945, decimal=2)
-    assert_almost_equal(atom_sites['Ba'].b_iso.value, desired=0.5226, decimal=2)
-    assert_almost_equal(atom_sites['Co'].b_iso.value, desired=0.2398, decimal=2)
-    assert_almost_equal(atom_sites['O'].b_iso.value, desired=1.4049, decimal=2)
+    assert_almost_equal(atom_sites['La'].adp_iso.value, desired=15.0945, decimal=2)
+    assert_almost_equal(atom_sites['Ba'].adp_iso.value, desired=0.5226, decimal=2)
+    assert_almost_equal(atom_sites['Co'].adp_iso.value, desired=0.2398, decimal=2)
+    assert_almost_equal(atom_sites['O'].adp_iso.value, desired=1.4049, decimal=2)
     assert_almost_equal(atom_sites['La'].occupancy.value, desired=0.011, decimal=2)
     assert_almost_equal(atom_sites['Ba'].occupancy.value, desired=1.3206, decimal=2)
 
@@ -277,11 +277,11 @@ def test_single_fit_neutron_pd_cwl_lbco_with_constraints() -> None:
     # Set aliases for parameters
     project.analysis.aliases.create(
         label='biso_La',
-        param=atom_sites['La'].b_iso,
+        param=atom_sites['La'].adp_iso,
     )
     project.analysis.aliases.create(
         label='biso_Ba',
-        param=atom_sites['Ba'].b_iso,
+        param=atom_sites['Ba'].adp_iso,
     )
     project.analysis.aliases.create(
         label='occ_La',
@@ -300,10 +300,10 @@ def test_single_fit_neutron_pd_cwl_lbco_with_constraints() -> None:
     project.analysis.fit()
 
     # Compare parameter values after fit
-    assert_almost_equal(atom_sites['La'].b_iso.value, desired=0.5443, decimal=2)
-    assert_almost_equal(atom_sites['Ba'].b_iso.value, desired=0.5443, decimal=2)
-    assert_almost_equal(atom_sites['Co'].b_iso.value, desired=0.2335, decimal=2)
-    assert_almost_equal(atom_sites['O'].b_iso.value, desired=1.4056, decimal=2)
+    assert_almost_equal(atom_sites['La'].adp_iso.value, desired=0.5443, decimal=2)
+    assert_almost_equal(atom_sites['Ba'].adp_iso.value, desired=0.5443, decimal=2)
+    assert_almost_equal(atom_sites['Co'].adp_iso.value, desired=0.2335, decimal=2)
+    assert_almost_equal(atom_sites['O'].adp_iso.value, desired=1.4056, decimal=2)
     assert_almost_equal(atom_sites['La'].occupancy.value, desired=0.5274, decimal=2)
     assert_almost_equal(atom_sites['Ba'].occupancy.value, desired=0.4726, decimal=2)
 
@@ -329,7 +329,7 @@ def test_fit_neutron_pd_cwl_hs() -> None:
         fract_y=0,
         fract_z=0.5,
         wyckoff_letter='b',
-        b_iso=0.1,
+        adp_iso=0.1,
     )
     model.atom_sites.create(
         label='Cu',
@@ -338,7 +338,7 @@ def test_fit_neutron_pd_cwl_hs() -> None:
         fract_y=0,
         fract_z=0,
         wyckoff_letter='e',
-        b_iso=1.2,
+        adp_iso=1.2,
     )
     model.atom_sites.create(
         label='O',
@@ -347,7 +347,7 @@ def test_fit_neutron_pd_cwl_hs() -> None:
         fract_y=-0.206,
         fract_z=0.061,
         wyckoff_letter='h',
-        b_iso=0.7,
+        adp_iso=0.7,
     )
     model.atom_sites.create(
         label='Cl',
@@ -356,7 +356,7 @@ def test_fit_neutron_pd_cwl_hs() -> None:
         fract_y=0,
         fract_z=0.197,
         wyckoff_letter='c',
-        b_iso=1.1,
+        adp_iso=1.1,
     )
     model.atom_sites.create(
         label='H',
@@ -365,7 +365,7 @@ def test_fit_neutron_pd_cwl_hs() -> None:
         fract_y=-0.132,
         fract_z=0.09,
         wyckoff_letter='h',
-        b_iso=2.3,
+        adp_iso=2.3,
     )
 
     # Set experiment
@@ -462,11 +462,11 @@ def test_fit_neutron_pd_cwl_hs() -> None:
     # ------------ 3rd fitting ------------
 
     # Select fitting parameters
-    model.atom_sites['Zn'].b_iso.free = True
-    model.atom_sites['Cu'].b_iso.free = True
-    model.atom_sites['O'].b_iso.free = True
-    model.atom_sites['Cl'].b_iso.free = True
-    model.atom_sites['H'].b_iso.free = True
+    model.atom_sites['Zn'].adp_iso.free = True
+    model.atom_sites['Cu'].adp_iso.free = True
+    model.atom_sites['O'].adp_iso.free = True
+    model.atom_sites['Cl'].adp_iso.free = True
+    model.atom_sites['H'].adp_iso.free = True
 
     # Perform fit
     project.analysis.fit()
@@ -490,11 +490,11 @@ def test_single_fit_neutron_pd_cwl_lbco_with_constraints_from_project(tmp_path)
     # Set constraints
     project.analysis.aliases.create(
         label='biso_La',
-        param=project.structures['lbco'].atom_sites['La'].b_iso,
+        param=project.structures['lbco'].atom_sites['La'].adp_iso,
     )
     project.analysis.aliases.create(
         label='biso_Ba',
-        param=project.structures['lbco'].atom_sites['Ba'].b_iso,
+        param=project.structures['lbco'].atom_sites['Ba'].adp_iso,
     )
 
     project.analysis.aliases.create(
diff --git a/tests/integration/fitting/test_powder-diffraction_joint-fit.py b/tests/integration/fitting/test_powder-diffraction_joint-fit.py
index fb94a8ff0..9bf55f79e 100644
--- a/tests/integration/fitting/test_powder-diffraction_joint-fit.py
+++ b/tests/integration/fitting/test_powder-diffraction_joint-fit.py
@@ -29,7 +29,7 @@ def test_joint_fit_split_dataset_neutron_pd_cwl_pbso4() -> None:
         fract_y=0.25,
         fract_z=0.167,
         wyckoff_letter='c',
-        b_iso=1.37,
+        adp_iso=1.37,
     )
     model.atom_sites.create(
         label='S',
@@ -38,7 +38,7 @@ def test_joint_fit_split_dataset_neutron_pd_cwl_pbso4() -> None:
         fract_y=0.25,
         fract_z=0.684,
         wyckoff_letter='c',
-        b_iso=0.3777,
+        adp_iso=0.3777,
     )
     model.atom_sites.create(
         label='O1',
@@ -47,7 +47,7 @@ def test_joint_fit_split_dataset_neutron_pd_cwl_pbso4() -> None:
         fract_y=0.25,
         fract_z=0.5954,
         wyckoff_letter='c',
-        b_iso=1.9764,
+        adp_iso=1.9764,
     )
     model.atom_sites.create(
         label='O2',
@@ -56,7 +56,7 @@ def test_joint_fit_split_dataset_neutron_pd_cwl_pbso4() -> None:
         fract_y=0.25,
         fract_z=0.5432,
         wyckoff_letter='c',
-        b_iso=1.4456,
+        adp_iso=1.4456,
     )
     model.atom_sites.create(
         label='O3',
@@ -65,7 +65,7 @@ def test_joint_fit_split_dataset_neutron_pd_cwl_pbso4() -> None:
         fract_y=0.0272,
         fract_z=0.8086,
         wyckoff_letter='d',
-        b_iso=1.2822,
+        adp_iso=1.2822,
     )
 
     # Set experiments
@@ -156,7 +156,7 @@ def test_joint_fit_neutron_xray_pd_cwl_pbso4() -> None:
         fract_y=0.25,
         fract_z=0.167,
         wyckoff_letter='c',
-        b_iso=1.37,
+        adp_iso=1.37,
     )
     model.atom_sites.create(
         label='S',
@@ -165,7 +165,7 @@ def test_joint_fit_neutron_xray_pd_cwl_pbso4() -> None:
         fract_y=0.25,
         fract_z=0.684,
         wyckoff_letter='c',
-        b_iso=0.3777,
+        adp_iso=0.3777,
     )
     model.atom_sites.create(
         label='O1',
@@ -174,7 +174,7 @@ def test_joint_fit_neutron_xray_pd_cwl_pbso4() -> None:
         fract_y=0.25,
         fract_z=0.5954,
         wyckoff_letter='c',
-        b_iso=1.9764,
+        adp_iso=1.9764,
     )
     model.atom_sites.create(
         label='O2',
@@ -183,7 +183,7 @@ def test_joint_fit_neutron_xray_pd_cwl_pbso4() -> None:
         fract_y=0.25,
         fract_z=0.5432,
         wyckoff_letter='c',
-        b_iso=1.4456,
+        adp_iso=1.4456,
     )
     model.atom_sites.create(
         label='O3',
@@ -192,7 +192,7 @@ def test_joint_fit_neutron_xray_pd_cwl_pbso4() -> None:
         fract_y=0.0272,
         fract_z=0.8086,
         wyckoff_letter='d',
-        b_iso=1.2822,
+        adp_iso=1.2822,
     )
 
     # Set experiments
diff --git a/tests/integration/fitting/test_powder-diffraction_time-of-flight.py b/tests/integration/fitting/test_powder-diffraction_time-of-flight.py
index c867e3fd8..c5dac22f0 100644
--- a/tests/integration/fitting/test_powder-diffraction_time-of-flight.py
+++ b/tests/integration/fitting/test_powder-diffraction_time-of-flight.py
@@ -26,7 +26,7 @@ def test_single_fit_neutron_pd_tof_si() -> None:
         fract_y=0.125,
         fract_z=0.125,
         wyckoff_letter='a',
-        b_iso=0.529,
+        adp_iso=0.529,
     )
 
     # Set experiment
@@ -62,7 +62,7 @@ def test_single_fit_neutron_pd_tof_si() -> None:
 
     # Select fitting parameters
     model.cell.length_a.free = True
-    model.atom_sites['Si'].b_iso.free = True
+    model.atom_sites['Si'].adp_iso.free = True
     expt.linked_phases['si'].scale.free = True
     expt.instrument.calib_d_to_tof_offset.free = True
     for point in expt.background:
@@ -92,7 +92,7 @@ def test_single_fit_neutron_pd_tof_ncaf() -> None:
         fract_y=0.0,
         fract_z=0.25,
         wyckoff_letter='b',
-        b_iso=0.9,
+        adp_iso=0.9,
     )
     model.atom_sites.create(
         label='Al',
@@ -101,7 +101,7 @@ def test_single_fit_neutron_pd_tof_ncaf() -> None:
         fract_y=0.25171,
         fract_z=0.25171,
         wyckoff_letter='a',
-        b_iso=0.66,
+        adp_iso=0.66,
     )
     model.atom_sites.create(
         label='Na',
@@ -110,7 +110,7 @@ def test_single_fit_neutron_pd_tof_ncaf() -> None:
         fract_y=0.08481,
         fract_z=0.08481,
         wyckoff_letter='a',
-        b_iso=1.9,
+        adp_iso=1.9,
     )
     model.atom_sites.create(
         label='F1',
@@ -119,7 +119,7 @@ def test_single_fit_neutron_pd_tof_ncaf() -> None:
         fract_y=0.3053,
         fract_z=0.1195,
         wyckoff_letter='c',
-        b_iso=0.9,
+        adp_iso=0.9,
     )
     model.atom_sites.create(
         label='F2',
@@ -128,7 +128,7 @@ def test_single_fit_neutron_pd_tof_ncaf() -> None:
         fract_y=0.3634,
         fract_z=0.1867,
         wyckoff_letter='c',
-        b_iso=1.28,
+        adp_iso=1.28,
     )
     model.atom_sites.create(
         label='F3',
@@ -137,7 +137,7 @@ def test_single_fit_neutron_pd_tof_ncaf() -> None:
         fract_y=0.4612,
         fract_z=0.4612,
         wyckoff_letter='a',
-        b_iso=0.79,
+        adp_iso=0.79,
     )
 
     # Set experiment
diff --git a/tests/integration/fitting/test_project_load.py b/tests/integration/fitting/test_project_load.py
index 53d8643f3..a7610956a 100644
--- a/tests/integration/fitting/test_project_load.py
+++ b/tests/integration/fitting/test_project_load.py
@@ -41,7 +41,7 @@ def _create_lbco_project() -> Project:
         fract_z=0,
         wyckoff_letter='a',
         occupancy=0.5,
-        b_iso=0.5,
+        adp_iso=0.5,
     )
     model.atom_sites.create(
         label='Ba',
@@ -51,7 +51,7 @@ def _create_lbco_project() -> Project:
         fract_z=0,
         wyckoff_letter='a',
         occupancy=0.5,
-        b_iso=0.5,
+        adp_iso=0.5,
     )
     model.atom_sites.create(
         label='Co',
@@ -60,7 +60,7 @@ def _create_lbco_project() -> Project:
         fract_y=0.5,
         fract_z=0.5,
         wyckoff_letter='b',
-        b_iso=0.5,
+        adp_iso=0.5,
     )
     model.atom_sites.create(
         label='O',
@@ -69,7 +69,7 @@ def _create_lbco_project() -> Project:
         fract_y=0.5,
         fract_z=0.5,
         wyckoff_letter='c',
-        b_iso=0.5,
+        adp_iso=0.5,
     )
 
     # Experiment
@@ -104,11 +104,11 @@ def _create_lbco_project() -> Project:
     # Aliases and constraints
     project.analysis.aliases.create(
         label='biso_La',
-        param=model.atom_sites['La'].b_iso,
+        param=model.atom_sites['La'].adp_iso,
     )
     project.analysis.aliases.create(
         label='biso_Ba',
-        param=model.atom_sites['Ba'].b_iso,
+        param=model.atom_sites['Ba'].adp_iso,
     )
     project.analysis.constraints.create(expression='biso_Ba = biso_La')
 
diff --git a/tests/integration/fitting/test_sequential.py b/tests/integration/fitting/test_sequential.py
index 4fb80209b..2583b9e10 100644
--- a/tests/integration/fitting/test_sequential.py
+++ b/tests/integration/fitting/test_sequential.py
@@ -39,7 +39,7 @@ def _create_sequential_project(tmp_path: Path) -> tuple[Project, str]:
         fract_z=0,
         wyckoff_letter='a',
         occupancy=0.5,
-        b_iso=0.5,
+        adp_iso=0.5,
     )
     model.atom_sites.create(
         label='Ba',
@@ -49,7 +49,7 @@ def _create_sequential_project(tmp_path: Path) -> tuple[Project, str]:
         fract_z=0,
         wyckoff_letter='a',
         occupancy=0.5,
-        b_iso=0.5,
+        adp_iso=0.5,
     )
     model.atom_sites.create(
         label='Co',
@@ -58,7 +58,7 @@ def _create_sequential_project(tmp_path: Path) -> tuple[Project, str]:
         fract_y=0.5,
         fract_z=0.5,
         wyckoff_letter='b',
-        b_iso=0.5,
+        adp_iso=0.5,
     )
     model.atom_sites.create(
         label='O',
@@ -67,7 +67,7 @@ def _create_sequential_project(tmp_path: Path) -> tuple[Project, str]:
         fract_y=0.5,
         fract_z=0.5,
         wyckoff_letter='c',
-        b_iso=0.5,
+        adp_iso=0.5,
     )
 
     # Experiment (template)
diff --git a/tests/integration/fitting/test_switch-calculator.py b/tests/integration/fitting/test_switch-calculator.py
index a195ac183..bd9a31956 100644
--- a/tests/integration/fitting/test_switch-calculator.py
+++ b/tests/integration/fitting/test_switch-calculator.py
@@ -21,11 +21,11 @@ def test_neutron_pd_cwl_lbco_crysfml(tmp_path) -> None:
     # Set constraints
     project.analysis.aliases.create(
         label='biso_La',
-        param=project.structures['lbco'].atom_sites['La'].b_iso,
+        param=project.structures['lbco'].atom_sites['La'].adp_iso,
     )
     project.analysis.aliases.create(
         label='biso_Ba',
-        param=project.structures['lbco'].atom_sites['Ba'].b_iso,
+        param=project.structures['lbco'].atom_sites['Ba'].adp_iso,
     )
 
     project.analysis.aliases.create(
diff --git a/tests/integration/scipp-analysis/dream/test_analyze_reduced_data.py b/tests/integration/scipp-analysis/dream/test_analyze_reduced_data.py
index 31496c4b2..f44695c95 100644
--- a/tests/integration/scipp-analysis/dream/test_analyze_reduced_data.py
+++ b/tests/integration/scipp-analysis/dream/test_analyze_reduced_data.py
@@ -84,7 +84,7 @@ def project_with_data(
         fract_y=0.125,
         fract_z=0.125,
         wyckoff_letter='c',
-        b_iso=1.1,
+        adp_iso=1.1,
     )
 
     # Step 3: Add experiment from modified CIF file
@@ -144,7 +144,7 @@ def fitted_project(
 
     # Step 5: Select parameters to be fitted
     # Set free parameters for structure
-    structure.atom_sites['C'].b_iso.free = True
+    structure.atom_sites['C'].adp_iso.free = True
 
     # Set free parameters for experiment
     experiment.linked_phases['diamond'].scale.free = True
diff --git a/tests/unit/easydiffraction/analysis/calculators/test_cryspy.py b/tests/unit/easydiffraction/analysis/calculators/test_cryspy.py
index 8593bfe0e..407577c19 100644
--- a/tests/unit/easydiffraction/analysis/calculators/test_cryspy.py
+++ b/tests/unit/easydiffraction/analysis/calculators/test_cryspy.py
@@ -18,6 +18,8 @@ def test_cryspy_calculator_engine_flag_and_converters():
 
     # Converters should just delegate/format without external deps
     class DummySample:
+        atom_sites = []
+
         @property
         def as_cif(self):
             return 'data_x'
diff --git a/tests/unit/easydiffraction/analysis/categories/test_aliases.py b/tests/unit/easydiffraction/analysis/categories/test_aliases.py
index 5efd265cf..81a936e53 100644
--- a/tests/unit/easydiffraction/analysis/categories/test_aliases.py
+++ b/tests/unit/easydiffraction/analysis/categories/test_aliases.py
@@ -10,9 +10,9 @@
 
 def test_alias_creation_and_collection():
     p1 = Parameter(
-        name='b_iso',
+        name='adp_iso',
         value_spec=AttributeSpec(default=0.5),
-        cif_handler=CifHandler(names=['_atom_site.b_iso']),
+        cif_handler=CifHandler(names=['_atom_site.adp_iso']),
     )
     a = Alias()
     a.label = 'x'
diff --git a/tests/unit/easydiffraction/analysis/test_fitting.py b/tests/unit/easydiffraction/analysis/test_fitting.py
index f63788c07..0f7ef88b1 100644
--- a/tests/unit/easydiffraction/analysis/test_fitting.py
+++ b/tests/unit/easydiffraction/analysis/test_fitting.py
@@ -13,9 +13,18 @@ def test_module_import():
 def test_fitter_early_exit_when_no_params(capsys, monkeypatch):
     from easydiffraction.analysis.fitting import Fitter
 
+    class DummyStructure:
+        _need_categories_update = False
+
+        def _update_categories(self):
+            pass
+
     class DummyStructures:
         free_parameters = []
 
+        def __iter__(self):
+            return iter([DummyStructure()])
+
     class DummyExperiment:
         parameters = []
 
@@ -46,9 +55,18 @@ class DummyParam:
         value = 1.0
         _fit_start_value = None
 
+    class DummyStructure:
+        _need_categories_update = False
+
+        def _update_categories(self):
+            pass
+
     class DummyStructures:
         free_parameters = [DummyParam()]
 
+        def __iter__(self):
+            return iter([DummyStructure()])
+
     class DummyExperiment:
         parameters = []
 
diff --git a/tests/unit/easydiffraction/datablocks/structure/categories/test_atom_site_aniso.py b/tests/unit/easydiffraction/datablocks/structure/categories/test_atom_site_aniso.py
new file mode 100644
index 000000000..831158e7e
--- /dev/null
+++ b/tests/unit/easydiffraction/datablocks/structure/categories/test_atom_site_aniso.py
@@ -0,0 +1,537 @@
+# SPDX-FileCopyrightText: 2026 EasyScience contributors <https://github.com/easyscience>
+# SPDX-License-Identifier: BSD-3-Clause
+"""Tests for atom_site_aniso category (default and factory)."""
+
+import math
+
+
+# ------------------------------------------------------------------
+#  Module import
+# ------------------------------------------------------------------
+
+
+def test_module_import():
+    import easydiffraction.datablocks.structure.categories.atom_site_aniso as MUT
+
+    expected_module_name = 'easydiffraction.datablocks.structure.categories.atom_site_aniso'
+    actual_module_name = MUT.__name__
+    assert expected_module_name == actual_module_name
+
+
+# ------------------------------------------------------------------
+#  Factory
+# ------------------------------------------------------------------
+
+
+class TestAtomSiteAnisoFactory:
+    def test_supported_tags(self):
+        from easydiffraction.datablocks.structure.categories.atom_site_aniso.factory import (
+            AtomSiteAnisoFactory,
+        )
+
+        tags = AtomSiteAnisoFactory.supported_tags()
+        assert 'default' in tags
+
+    def test_default_tag(self):
+        from easydiffraction.datablocks.structure.categories.atom_site_aniso.factory import (
+            AtomSiteAnisoFactory,
+        )
+
+        assert AtomSiteAnisoFactory.default_tag() == 'default'
+
+    def test_create(self):
+        from easydiffraction.datablocks.structure.categories.atom_site_aniso.default import (
+            AtomSiteAnisoCollection,
+        )
+        from easydiffraction.datablocks.structure.categories.atom_site_aniso.factory import (
+            AtomSiteAnisoFactory,
+        )
+
+        obj = AtomSiteAnisoFactory.create('default')
+        assert isinstance(obj, AtomSiteAnisoCollection)
+
+
+# ------------------------------------------------------------------
+#  AtomSiteAniso item
+# ------------------------------------------------------------------
+
+
+class TestAtomSiteAniso:
+    def test_instantiation(self):
+        from easydiffraction.datablocks.structure.categories.atom_site_aniso.default import (
+            AtomSiteAniso,
+        )
+
+        entry = AtomSiteAniso()
+        assert entry is not None
+
+    def test_identity_category_code(self):
+        from easydiffraction.datablocks.structure.categories.atom_site_aniso.default import (
+            AtomSiteAniso,
+        )
+
+        entry = AtomSiteAniso()
+        assert entry._identity.category_code == 'atom_site_aniso'
+
+    def test_defaults(self):
+        from easydiffraction.datablocks.structure.categories.atom_site_aniso.default import (
+            AtomSiteAniso,
+        )
+
+        entry = AtomSiteAniso()
+        assert entry.label.value == ''
+        assert entry.adp_11.value == 0.0
+        assert entry.adp_22.value == 0.0
+        assert entry.adp_33.value == 0.0
+        assert entry.adp_12.value == 0.0
+        assert entry.adp_13.value == 0.0
+        assert entry.adp_23.value == 0.0
+
+    def test_label_setter(self):
+        from easydiffraction.datablocks.structure.categories.atom_site_aniso.default import (
+            AtomSiteAniso,
+        )
+
+        entry = AtomSiteAniso()
+        entry.label = 'Si'
+        assert entry.label.value == 'Si'
+
+    def test_tensor_setters(self):
+        from easydiffraction.datablocks.structure.categories.atom_site_aniso.default import (
+            AtomSiteAniso,
+        )
+
+        entry = AtomSiteAniso()
+        entry.adp_11 = 0.01
+        entry.adp_22 = 0.02
+        entry.adp_33 = 0.03
+        entry.adp_12 = 0.04
+        entry.adp_13 = 0.05
+        entry.adp_23 = 0.06
+        assert entry.adp_11.value == 0.01
+        assert entry.adp_22.value == 0.02
+        assert entry.adp_33.value == 0.03
+        assert entry.adp_12.value == 0.04
+        assert entry.adp_13.value == 0.05
+        assert entry.adp_23.value == 0.06
+
+    def test_dual_cif_names(self):
+        from easydiffraction.datablocks.structure.categories.atom_site_aniso.default import (
+            AtomSiteAniso,
+        )
+
+        entry = AtomSiteAniso()
+        # Default order: B first
+        assert entry._adp_11._cif_handler.names[0] == '_atom_site_aniso.B_11'
+        assert entry._adp_11._cif_handler.names[1] == '_atom_site_aniso.U_11'
+
+    def test_identity_entry_name_follows_label(self):
+        from easydiffraction.datablocks.structure.categories.atom_site_aniso.default import (
+            AtomSiteAniso,
+        )
+
+        entry = AtomSiteAniso()
+        entry.label = 'Fe1'
+        assert entry._identity.category_entry_name == 'Fe1'
+
+
+# ------------------------------------------------------------------
+#  AtomSiteAnisoCollection
+# ------------------------------------------------------------------
+
+
+class TestAtomSiteAnisoCollection:
+    def test_type_info(self):
+        from easydiffraction.datablocks.structure.categories.atom_site_aniso.default import (
+            AtomSiteAnisoCollection,
+        )
+
+        assert AtomSiteAnisoCollection.type_info.tag == 'default'
+
+    def test_instantiation(self):
+        from easydiffraction.datablocks.structure.categories.atom_site_aniso.default import (
+            AtomSiteAnisoCollection,
+        )
+
+        coll = AtomSiteAnisoCollection()
+        assert coll is not None
+        assert len(coll) == 0
+
+    def test_skip_cif_serialization_no_parent(self):
+        from easydiffraction.datablocks.structure.categories.atom_site_aniso.default import (
+            AtomSiteAnisoCollection,
+        )
+
+        coll = AtomSiteAnisoCollection()
+        # No parent → should skip
+        assert coll._skip_cif_serialization() is True
+
+    def test_skip_cif_serialization_isotropic(self):
+        from easydiffraction.datablocks.structure.item.base import Structure
+
+        structure = Structure(name='test')
+        structure.atom_sites.create(label='Si', type_symbol='Si', adp_type='Biso', adp_iso=0.5)
+        structure._sync_atom_site_aniso()
+        assert structure.atom_site_aniso._skip_cif_serialization() is True
+
+    def test_skip_cif_serialization_anisotropic(self):
+        from easydiffraction.datablocks.structure.item.base import Structure
+
+        structure = Structure(name='test')
+        structure.atom_sites.create(label='Si', type_symbol='Si', adp_type='Biso', adp_iso=0.5)
+        structure._sync_atom_site_aniso()
+        structure.atom_sites['Si'].adp_type = 'Bani'
+        assert structure.atom_site_aniso._skip_cif_serialization() is False
+
+
+# ------------------------------------------------------------------
+#  Structure ↔ aniso sync
+# ------------------------------------------------------------------
+
+
+class TestStructureAnisoSync:
+    def test_sync_adds_missing_entries(self):
+        from easydiffraction.datablocks.structure.item.base import Structure
+
+        structure = Structure(name='test')
+        structure.atom_sites.create(label='Si', type_symbol='Si')
+        structure._sync_atom_site_aniso()
+        assert 'Si' in structure.atom_site_aniso
+        assert structure.atom_site_aniso['Si'].label.value == 'Si'
+
+    def test_sync_removes_stale_entries(self):
+        from easydiffraction.datablocks.structure.item.base import Structure
+
+        structure = Structure(name='test')
+        structure.atom_sites.create(label='Si', type_symbol='Si')
+        structure.atom_sites.create(label='O', type_symbol='O')
+        structure._sync_atom_site_aniso()
+        assert len(structure.atom_site_aniso) == 2
+
+        structure.atom_sites.remove('O')
+        structure._sync_atom_site_aniso()
+        assert len(structure.atom_site_aniso) == 1
+        assert 'Si' in structure.atom_site_aniso
+
+    def test_sync_multiple_atoms(self):
+        from easydiffraction.datablocks.structure.item.base import Structure
+
+        structure = Structure(name='test')
+        structure.atom_sites.create(label='La', type_symbol='La')
+        structure.atom_sites.create(label='Ba', type_symbol='Ba')
+        structure.atom_sites.create(label='Co', type_symbol='Co')
+        structure._sync_atom_site_aniso()
+        assert len(structure.atom_site_aniso) == 3
+        for lbl in ('La', 'Ba', 'Co'):
+            assert lbl in structure.atom_site_aniso
+
+
+# ------------------------------------------------------------------
+#  ADP type conversion (iso ↔ ani)
+# ------------------------------------------------------------------
+
+
+class TestAdpTypeConversion:
+    def _make_structure_with_atom(self, adp_type='Biso', adp_iso=0.5):
+        from easydiffraction.datablocks.structure.item.base import Structure
+
+        structure = Structure(name='test')
+        structure.atom_sites.create(
+            label='Si',
+            type_symbol='Si',
+            adp_type=adp_type,
+            adp_iso=adp_iso,
+        )
+        structure._sync_atom_site_aniso()
+        return structure
+
+    def test_biso_to_bani_seeds_diagonal(self):
+        structure = self._make_structure_with_atom(adp_type='Biso', adp_iso=0.5)
+        structure.atom_sites['Si'].adp_type = 'Bani'
+        aniso = structure.atom_site_aniso['Si']
+        assert aniso.adp_11.value == 0.5
+        assert aniso.adp_22.value == 0.5
+        assert aniso.adp_33.value == 0.5
+        assert aniso.adp_12.value == 0.0
+        assert aniso.adp_13.value == 0.0
+        assert aniso.adp_23.value == 0.0
+
+    def test_biso_to_uani_seeds_converted_diagonal(self):
+        factor = 8.0 * math.pi**2
+        structure = self._make_structure_with_atom(adp_type='Biso', adp_iso=0.5)
+        structure.atom_sites['Si'].adp_type = 'Uani'
+        aniso = structure.atom_site_aniso['Si']
+        expected_u = 0.5 / factor
+        assert math.isclose(aniso.adp_11.value, expected_u, rel_tol=1e-10)
+        assert math.isclose(aniso.adp_22.value, expected_u, rel_tol=1e-10)
+        assert math.isclose(aniso.adp_33.value, expected_u, rel_tol=1e-10)
+
+    def test_bani_to_biso_collapses_diagonal(self):
+        structure = self._make_structure_with_atom(adp_type='Biso', adp_iso=0.5)
+        structure.atom_sites['Si'].adp_type = 'Bani'
+        # Modify diagonal
+        aniso = structure.atom_site_aniso['Si']
+        aniso.adp_11 = 0.3
+        aniso.adp_22 = 0.6
+        aniso.adp_33 = 0.9
+        structure.atom_sites['Si'].adp_type = 'Biso'
+        expected = (0.3 + 0.6 + 0.9) / 3.0
+        assert math.isclose(structure.atom_sites['Si'].adp_iso.value, expected, rel_tol=1e-10)
+
+    def test_uiso_to_uani_seeds_diagonal(self):
+        structure = self._make_structure_with_atom(adp_type='Uiso', adp_iso=0.05)
+        structure.atom_sites['Si'].adp_type = 'Uani'
+        aniso = structure.atom_site_aniso['Si']
+        assert math.isclose(aniso.adp_11.value, 0.05, rel_tol=1e-10)
+
+    def test_bani_to_uani_converts_values(self):
+        factor = 8.0 * math.pi**2
+        structure = self._make_structure_with_atom(adp_type='Biso', adp_iso=0.5)
+        structure.atom_sites['Si'].adp_type = 'Bani'
+        # Now ani values are B=0.5
+        structure.atom_sites['Si'].adp_type = 'Uani'
+        aniso = structure.atom_site_aniso['Si']
+        expected_u = 0.5 / factor
+        assert math.isclose(aniso.adp_11.value, expected_u, rel_tol=1e-10)
+
+    def test_round_trip_biso_uani_biso(self):
+        structure = self._make_structure_with_atom(adp_type='Biso', adp_iso=0.5)
+        structure.atom_sites['Si'].adp_type = 'Uani'
+        structure.atom_sites['Si'].adp_type = 'Biso'
+        assert math.isclose(structure.atom_sites['Si'].adp_iso.value, 0.5, rel_tol=1e-10)
+
+
+# ------------------------------------------------------------------
+#  CIF name reordering
+# ------------------------------------------------------------------
+
+
+class TestCifNameReordering:
+    def test_biso_cif_names_default_order(self):
+        from easydiffraction.datablocks.structure.categories.atom_sites.default import AtomSite
+
+        site = AtomSite()
+        assert site._adp_iso._cif_handler.names[0] == '_atom_site.B_iso_or_equiv'
+
+    def test_uiso_reorders_iso_cif_names(self):
+        from easydiffraction.datablocks.structure.item.base import Structure
+
+        structure = Structure(name='test')
+        structure.atom_sites.create(label='Si', type_symbol='Si', adp_type='Biso', adp_iso=0.5)
+        structure._sync_atom_site_aniso()
+        structure.atom_sites['Si'].adp_type = 'Uiso'
+        assert (
+            structure.atom_sites['Si']._adp_iso._cif_handler.names[0]
+            == '_atom_site.U_iso_or_equiv'
+        )
+
+    def test_bani_reorders_aniso_cif_names(self):
+        from easydiffraction.datablocks.structure.item.base import Structure
+
+        structure = Structure(name='test')
+        structure.atom_sites.create(label='Si', type_symbol='Si', adp_type='Biso', adp_iso=0.5)
+        structure._sync_atom_site_aniso()
+        structure.atom_sites['Si'].adp_type = 'Bani'
+        aniso = structure.atom_site_aniso['Si']
+        assert aniso._adp_11._cif_handler.names[0] == '_atom_site_aniso.B_11'
+
+    def test_uani_reorders_aniso_cif_names(self):
+        from easydiffraction.datablocks.structure.item.base import Structure
+
+        structure = Structure(name='test')
+        structure.atom_sites.create(label='Si', type_symbol='Si', adp_type='Biso', adp_iso=0.5)
+        structure._sync_atom_site_aniso()
+        structure.atom_sites['Si'].adp_type = 'Uani'
+        aniso = structure.atom_site_aniso['Si']
+        assert aniso._adp_11._cif_handler.names[0] == '_atom_site_aniso.U_11'
+
+
+# ------------------------------------------------------------------
+#  _iso_labels helper
+# ------------------------------------------------------------------
+
+
+class TestIsoLabels:
+    def test_all_iso_returns_all_labels(self):
+        from easydiffraction.datablocks.structure.item.base import Structure
+
+        structure = Structure(name='test')
+        structure.atom_sites.create(label='A', type_symbol='Si', adp_type='Biso', adp_iso=0.5)
+        structure.atom_sites.create(label='B', type_symbol='O', adp_type='Uiso', adp_iso=0.01)
+        structure._sync_atom_site_aniso()
+        labels = structure.atom_site_aniso._iso_labels()
+        assert labels == {'A', 'B'}
+
+    def test_all_aniso_returns_empty(self):
+        from easydiffraction.datablocks.structure.item.base import Structure
+
+        structure = Structure(name='test')
+        structure.atom_sites.create(label='A', type_symbol='Si', adp_type='Biso', adp_iso=0.5)
+        structure._sync_atom_site_aniso()
+        structure.atom_sites['A'].adp_type = 'Bani'
+        labels = structure.atom_site_aniso._iso_labels()
+        assert labels == set()
+
+    def test_mixed_returns_only_iso(self):
+        from easydiffraction.datablocks.structure.item.base import Structure
+
+        structure = Structure(name='test')
+        structure.atom_sites.create(label='A', type_symbol='Si', adp_type='Biso', adp_iso=0.5)
+        structure.atom_sites.create(label='B', type_symbol='O', adp_type='Biso', adp_iso=0.3)
+        structure._sync_atom_site_aniso()
+        structure.atom_sites['A'].adp_type = 'Bani'
+        labels = structure.atom_site_aniso._iso_labels()
+        assert labels == {'B'}
+
+    def test_no_parent_returns_empty(self):
+        from easydiffraction.datablocks.structure.categories.atom_site_aniso.default import (
+            AtomSiteAnisoCollection,
+        )
+
+        coll = AtomSiteAnisoCollection()
+        assert coll._iso_labels() == set()
+
+
+# ------------------------------------------------------------------
+#  _format_cif_row (? for iso atoms)
+# ------------------------------------------------------------------
+
+
+class TestFormatCifRow:
+    def _make_structure(self):
+        from easydiffraction.datablocks.structure.item.base import Structure
+
+        structure = Structure(name='test')
+        structure.atom_sites.create(label='A', type_symbol='Si', adp_type='Biso', adp_iso=0.5)
+        structure.atom_sites.create(label='B', type_symbol='O', adp_type='Biso', adp_iso=0.3)
+        structure._sync_atom_site_aniso()
+        return structure
+
+    def test_iso_atom_gets_question_marks(self):
+        structure = self._make_structure()
+        structure.atom_sites['A'].adp_type = 'Bani'
+        aniso_coll = structure.atom_site_aniso
+        row = aniso_coll._format_cif_row(aniso_coll['B'])
+        assert row is not None
+        assert len(row) == 7
+        assert row[0] == 'B'
+        assert all(v == '?' for v in row[1:])
+
+    def test_aniso_atom_returns_none(self):
+        structure = self._make_structure()
+        structure.atom_sites['A'].adp_type = 'Bani'
+        aniso_coll = structure.atom_site_aniso
+        row = aniso_coll._format_cif_row(aniso_coll['A'])
+        assert row is None
+
+    def test_cif_output_has_question_marks_for_iso(self):
+        structure = self._make_structure()
+        structure.atom_sites['A'].adp_type = 'Bani'
+        cif = structure.atom_site_aniso.as_cif
+        lines = cif.strip().split('\n')
+        data_lines = [l for l in lines if not l.startswith(('loop_', '_atom_site_aniso'))]
+        # B is iso → should have ?
+        b_line = next(l for l in data_lines if l.strip().startswith('B'))
+        assert '?' in b_line
+        # A is aniso → should not have ?
+        a_line = next(l for l in data_lines if l.strip().startswith('A'))
+        assert '?' not in a_line
+
+    def test_all_aniso_no_question_marks(self):
+        structure = self._make_structure()
+        structure.atom_sites['A'].adp_type = 'Bani'
+        structure.atom_sites['B'].adp_type = 'Bani'
+        cif = structure.atom_site_aniso.as_cif
+        assert '?' not in cif
+
+    def test_all_iso_cif_suppressed(self):
+        structure = self._make_structure()
+        cif = structure.atom_site_aniso.as_cif
+        assert cif == ''
+
+
+# ------------------------------------------------------------------
+#  Additional ADP type switching paths
+# ------------------------------------------------------------------
+
+
+class TestAdpTypeSwitchingPaths:
+    def _make_structure(self, adp_type='Biso', adp_iso=0.5):
+        from easydiffraction.datablocks.structure.item.base import Structure
+
+        structure = Structure(name='test')
+        structure.atom_sites.create(
+            label='Si',
+            type_symbol='Si',
+            adp_type=adp_type,
+            adp_iso=adp_iso,
+        )
+        structure._sync_atom_site_aniso()
+        return structure
+
+    def test_uani_to_uiso_collapses(self):
+        structure = self._make_structure(adp_type='Uiso', adp_iso=0.05)
+        structure.atom_sites['Si'].adp_type = 'Uani'
+        aniso = structure.atom_site_aniso['Si']
+        aniso.adp_11 = 0.01
+        aniso.adp_22 = 0.02
+        aniso.adp_33 = 0.03
+        structure.atom_sites['Si'].adp_type = 'Uiso'
+        expected = (0.01 + 0.02 + 0.03) / 3.0
+        assert math.isclose(structure.atom_sites['Si'].adp_iso.value, expected, rel_tol=1e-10)
+
+    def test_uani_to_biso_converts_and_collapses(self):
+        factor = 8.0 * math.pi**2
+        structure = self._make_structure(adp_type='Uiso', adp_iso=0.05)
+        structure.atom_sites['Si'].adp_type = 'Uani'
+        aniso = structure.atom_site_aniso['Si']
+        aniso.adp_11 = 0.01
+        aniso.adp_22 = 0.02
+        aniso.adp_33 = 0.03
+        structure.atom_sites['Si'].adp_type = 'Biso'
+        expected_b = (0.01 + 0.02 + 0.03) / 3.0 * factor
+        assert math.isclose(structure.atom_sites['Si'].adp_iso.value, expected_b, rel_tol=1e-10)
+
+    def test_uani_to_bani_converts_values(self):
+        factor = 8.0 * math.pi**2
+        structure = self._make_structure(adp_type='Uiso', adp_iso=0.05)
+        structure.atom_sites['Si'].adp_type = 'Uani'
+        structure.atom_sites['Si'].adp_type = 'Bani'
+        aniso = structure.atom_site_aniso['Si']
+        expected_b = 0.05 * factor
+        assert math.isclose(aniso.adp_11.value, expected_b, rel_tol=1e-10)
+
+    def test_biso_to_uiso_converts(self):
+        factor = 8.0 * math.pi**2
+        structure = self._make_structure(adp_type='Biso', adp_iso=0.5)
+        structure.atom_sites['Si'].adp_type = 'Uiso'
+        expected_u = 0.5 / factor
+        assert math.isclose(structure.atom_sites['Si'].adp_iso.value, expected_u, rel_tol=1e-10)
+
+    def test_uiso_to_biso_converts(self):
+        factor = 8.0 * math.pi**2
+        u_val = 0.005
+        structure = self._make_structure(adp_type='Uiso', adp_iso=u_val)
+        structure.atom_sites['Si'].adp_type = 'Biso'
+        expected_b = u_val * factor
+        assert math.isclose(structure.atom_sites['Si'].adp_iso.value, expected_b, rel_tol=1e-10)
+
+    def test_round_trip_uiso_bani_uiso(self):
+        structure = self._make_structure(adp_type='Uiso', adp_iso=0.05)
+        structure.atom_sites['Si'].adp_type = 'Bani'
+        structure.atom_sites['Si'].adp_type = 'Uiso'
+        assert math.isclose(structure.atom_sites['Si'].adp_iso.value, 0.05, rel_tol=1e-10)
+
+    def test_round_trip_biso_bani_biso(self):
+        structure = self._make_structure(adp_type='Biso', adp_iso=0.5)
+        structure.atom_sites['Si'].adp_type = 'Bani'
+        structure.atom_sites['Si'].adp_type = 'Biso'
+        assert math.isclose(structure.atom_sites['Si'].adp_iso.value, 0.5, rel_tol=1e-10)
+
+    def test_adp_iso_not_free_when_aniso(self):
+        structure = self._make_structure(adp_type='Biso', adp_iso=0.5)
+        structure.space_group.name_h_m = 'P m -3 m'
+        structure.atom_sites['Si'].adp_iso.free = True
+        structure.atom_sites['Si'].adp_type = 'Bani'
+        structure.atom_sites._update()
+        assert structure.atom_sites['Si'].adp_iso.free is False
diff --git a/tests/unit/easydiffraction/datablocks/structure/categories/test_atom_sites.py b/tests/unit/easydiffraction/datablocks/structure/categories/test_atom_sites.py
index e47cd084f..60a74a683 100644
--- a/tests/unit/easydiffraction/datablocks/structure/categories/test_atom_sites.py
+++ b/tests/unit/easydiffraction/datablocks/structure/categories/test_atom_sites.py
@@ -60,7 +60,7 @@ def test_defaults(self):
         assert site.fract_y.value == 0.0
         assert site.fract_z.value == 0.0
         assert site.occupancy.value == 1.0
-        assert site.b_iso.value == 0.0
+        assert site.adp_iso.value == 0.0
         assert site.adp_type.value == 'Biso'
 
     def test_label_setter(self):
@@ -95,12 +95,12 @@ def test_occupancy_setter(self):
         site.occupancy = 0.5
         assert site.occupancy.value == 0.5
 
-    def test_b_iso_setter(self):
+    def test_adp_iso_setter(self):
         from easydiffraction.datablocks.structure.categories.atom_sites.default import AtomSite
 
         site = AtomSite()
-        site.b_iso = 1.5
-        assert site.b_iso.value == 1.5
+        site.adp_iso = 1.5
+        assert site.adp_iso.value == 1.5
 
     def test_type_symbol_allowed_values(self):
         from easydiffraction.datablocks.structure.categories.atom_sites.default import AtomSite
@@ -130,3 +130,120 @@ def test_instantiation(self):
 
         sites = AtomSites()
         assert sites is not None
+
+
+# ------------------------------------------------------------------
+#  _sync_iso_from_aniso
+# ------------------------------------------------------------------
+
+
+class TestSyncIsoFromAniso:
+    def _make_structure(self, adp_type='Biso', adp_iso=0.5):
+        from easydiffraction.datablocks.structure.item.base import Structure
+
+        structure = Structure(name='test')
+        structure.atom_sites.create(
+            label='Si',
+            type_symbol='Si',
+            adp_type=adp_type,
+            adp_iso=adp_iso,
+        )
+        structure._sync_atom_site_aniso()
+        return structure
+
+    def test_sync_updates_iso_for_bani_atom(self):
+        import math
+
+        structure = self._make_structure(adp_type='Biso', adp_iso=0.5)
+        structure.atom_sites['Si'].adp_type = 'Bani'
+        aniso = structure.atom_site_aniso['Si']
+        aniso.adp_11 = 0.3
+        aniso.adp_22 = 0.6
+        aniso.adp_33 = 0.9
+        structure.atom_sites._sync_iso_from_aniso()
+        expected = (0.3 + 0.6 + 0.9) / 3.0
+        assert math.isclose(structure.atom_sites['Si'].adp_iso.value, expected, rel_tol=1e-10)
+
+    def test_sync_updates_iso_for_uani_atom(self):
+        import math
+
+        structure = self._make_structure(adp_type='Uiso', adp_iso=0.05)
+        structure.atom_sites['Si'].adp_type = 'Uani'
+        aniso = structure.atom_site_aniso['Si']
+        aniso.adp_11 = 0.01
+        aniso.adp_22 = 0.02
+        aniso.adp_33 = 0.03
+        structure.atom_sites._sync_iso_from_aniso()
+        expected = (0.01 + 0.02 + 0.03) / 3.0
+        assert math.isclose(structure.atom_sites['Si'].adp_iso.value, expected, rel_tol=1e-10)
+
+    def test_sync_skips_iso_atoms(self):
+        structure = self._make_structure(adp_type='Biso', adp_iso=0.5)
+        structure.atom_sites._sync_iso_from_aniso()
+        assert structure.atom_sites['Si'].adp_iso.value == 0.5
+
+    def test_update_calls_sync(self):
+        """Verify _update() triggers _sync_iso_from_aniso().
+
+        In P m -3 m Wyckoff a, symmetry forces U11=U22=U33.
+        We set all diags to 0.3 (satisfying the constraint), then
+        manually overwrite adp_iso to a wrong value.  After _update(),
+        adp_iso must be resynced from the (still-equal) diags.
+        """
+        structure = self._make_structure(adp_type='Biso', adp_iso=0.5)
+        structure.space_group.name_h_m = 'P m -3 m'
+        structure.atom_sites['Si'].adp_type = 'Bani'
+        aniso = structure.atom_site_aniso['Si']
+        aniso.adp_11 = 0.3
+        aniso.adp_22 = 0.3
+        aniso.adp_33 = 0.3
+        # Force adp_iso to a wrong value so we can confirm _update resyncs it
+        structure.atom_sites['Si'].adp_iso = 0.99
+        structure.atom_sites._update()
+        assert structure.atom_sites['Si'].adp_iso.value == 0.3
+
+
+# ------------------------------------------------------------------
+#  adp_iso_as_b property
+# ------------------------------------------------------------------
+
+
+class TestAdpIsoAsB:
+    def _make_structure(self, adp_type='Biso', adp_iso=0.5):
+        from easydiffraction.datablocks.structure.item.base import Structure
+
+        structure = Structure(name='test')
+        structure.atom_sites.create(
+            label='Si',
+            type_symbol='Si',
+            adp_type=adp_type,
+            adp_iso=adp_iso,
+        )
+        structure._sync_atom_site_aniso()
+        return structure
+
+    def test_biso_as_b_returns_same_value(self):
+        structure = self._make_structure(adp_type='Biso', adp_iso=0.5)
+        assert structure.atom_sites['Si'].adp_iso_as_b == 0.5
+
+    def test_uiso_as_b_converts(self):
+        import math
+
+        u_val = 0.005
+        structure = self._make_structure(adp_type='Uiso', adp_iso=u_val)
+        expected_b = u_val * 8.0 * math.pi**2
+        assert math.isclose(structure.atom_sites['Si'].adp_iso_as_b, expected_b, rel_tol=1e-10)
+
+    def test_bani_as_b_returns_iso_value(self):
+        structure = self._make_structure(adp_type='Biso', adp_iso=0.5)
+        structure.atom_sites['Si'].adp_type = 'Bani'
+        assert structure.atom_sites['Si'].adp_iso_as_b == 0.5
+
+    def test_uani_as_b_converts(self):
+        import math
+
+        u_val = 0.005
+        structure = self._make_structure(adp_type='Uiso', adp_iso=u_val)
+        structure.atom_sites['Si'].adp_type = 'Uani'
+        expected_b = u_val * 8.0 * math.pi**2
+        assert math.isclose(structure.atom_sites['Si'].adp_iso_as_b, expected_b, rel_tol=1e-10)
diff --git a/tests/unit/easydiffraction/io/cif/test_serialize.py b/tests/unit/easydiffraction/io/cif/test_serialize.py
index e79d0d972..fc8f1fa2f 100644
--- a/tests/unit/easydiffraction/io/cif/test_serialize.py
+++ b/tests/unit/easydiffraction/io/cif/test_serialize.py
@@ -13,8 +13,8 @@ def test_module_import():
 def test_format_value_quotes_whitespace_strings():
     import easydiffraction.io.cif.serialize as MUT
 
-    assert MUT.format_value('a b') == '       "a b"'
-    assert MUT.format_value('ab') == '          ab'
+    assert MUT.format_value('a b') == '"a b"'
+    assert MUT.format_value('ab') == 'ab'
 
 
 def test_param_to_cif_minimal():
@@ -27,7 +27,7 @@ def __init__(self):
             self.value = 3
 
     p = P()
-    assert MUT.param_to_cif(p) == '_x.y   3.00000000'
+    assert MUT.param_to_cif(p) == '_x.y 3.00000000'
 
 
 def test_category_collection_to_cif_empty_and_one_row():
diff --git a/tests/unit/easydiffraction/io/cif/test_serialize_more.py b/tests/unit/easydiffraction/io/cif/test_serialize_more.py
index 8be11b204..f8e5dfd25 100644
--- a/tests/unit/easydiffraction/io/cif/test_serialize_more.py
+++ b/tests/unit/easydiffraction/io/cif/test_serialize_more.py
@@ -34,7 +34,7 @@ def __init__(self):
 
     out = MUT.datablock_item_to_cif(DB())
     assert out.startswith('data_block1')
-    assert '_aa  42.0000' in out
+    assert '_aa 42.0000' in out
     assert 'loop_' in out
     assert '_aa' in out
     assert '7' in out
diff --git a/tests/unit/easydiffraction/project/test_project_load.py b/tests/unit/easydiffraction/project/test_project_load.py
index 807cb580b..bea053200 100644
--- a/tests/unit/easydiffraction/project/test_project_load.py
+++ b/tests/unit/easydiffraction/project/test_project_load.py
@@ -46,7 +46,7 @@ def test_round_trips_structure(self, tmp_path):
             fract_x=0.0,
             fract_y=0.0,
             fract_z=0.0,
-            b_iso=0.5,
+            adp_iso=0.5,
         )
         original.save_as(str(tmp_path / 'proj'))
 
@@ -58,7 +58,7 @@ def test_round_trips_structure(self, tmp_path):
         assert abs(ls.cell.length_a.value - 3.88) < 1e-6
         assert len(ls.atom_sites) == 1
         assert ls.atom_sites['Co'].type_symbol.value == 'Co'
-        assert abs(ls.atom_sites['Co'].b_iso.value - 0.5) < 1e-6
+        assert abs(ls.atom_sites['Co'].adp_iso.value - 0.5) < 1e-6
 
 
 class TestLoadAnalysis:
diff --git a/tests/unit/easydiffraction/summary/test_summary_details.py b/tests/unit/easydiffraction/summary/test_summary_details.py
index 2ada0f573..98dcc1027 100644
--- a/tests/unit/easydiffraction/summary/test_summary_details.py
+++ b/tests/unit/easydiffraction/summary/test_summary_details.py
@@ -32,7 +32,7 @@ def __init__(self, label, typ, x, y, z, occ, biso):
         self.fract_y = _Val(y)
         self.fract_z = _Val(z)
         self.occupancy = _Val(occ)
-        self.b_iso = _Val(biso)
+        self.adp_iso = _Val(biso)
 
 
 class _Model: