CLuster Expansion in Atomistic Simulation Environment (clease)

1.2.0 · active · verified Fri Apr 17

CLEASE (CLuster Expansion in Atomistic Simulation Environment) is a Python package for constructing and handling cluster expansion Hamiltonians for materials simulations, often used in conjunction with ASE. It is currently at version 1.2.0 and receives updates periodically, with the last major release in April 2024.

Common errors

```
NameError: name 'CEConfig' is not defined
```
cause Using the old class name 'CEConfig' which was renamed in clease v1.1.0.

fix Replace `CEConfig` with `CEBulk`. For slab calculations, `CESlab` was renamed to `CEPrism`.
```
AttributeError: module 'clease' has no attribute 'sqs'
```
cause Attempting to use the `clease.sqs` module, which was removed in clease v1.2.0.

fix Install and use the `sqsgenerator` library directly for SQS functionality, as it is no longer integrated into `clease`.
```
TypeError: 'float' object is not iterable
```
cause Providing a single float value to `Settings(max_cluster_dia=...)` instead of a list.

fix Ensure `max_cluster_dia` is a list, e.g., `Settings(max_cluster_dia=[3.0, 4.0, 5.0])`.

Warnings

breaking The main classes `CEConfig` and `CESlab` were renamed to `CEBulk` and `CEPrism` respectively.
Fix: Update your imports and class instantiations: `CEConfig(...)` becomes `CEBulk(...)` and `CESlab(...)` becomes `CEPrism(...)`.
breaking The `clease.sqs` module, which provided functionality for generating Special Quasirandom Structures, has been removed.
Fix: For SQS generation, migrate to the dedicated `sqsgenerator` library, which CLEASE now recommends as an external dependency.
gotcha The `max_cluster_dia` parameter in `clease.Settings` expects a list of floats (one for each cluster order), not a single float.
Fix: Pass `max_cluster_dia` as a list, e.g., `max_cluster_dia=[3.0, 4.0, 5.0]` for 2-body, 3-body, and 4-body clusters respectively.

Install

pip install clease Install latest version

Imports

CEBulk
wrong:
```
from clease import CEConfig
```
correct:
```
from clease import CEBulk
```
CEConfig was renamed to CEBulk in v1.1.0.
CEPrism
wrong:
```
from clease import CESlab
```
correct:
```
from clease import CEPrism
```
CESlab was renamed to CEPrism in v1.1.0.
Settings
```
from clease import Settings
```
Concentration
```
from clease import Concentration
```

Quickstart

Initializes a basic Cluster Expansion Bulk (CEBulk) object using an ASE primitive cell, defines concentrations, and sets up the cluster expansion parameters.

from ase.build import bulk
from clease import CEBulk, Concentration, Settings

# 1. Define primitive cell using ASE
prim = bulk("Cu", "fcc", a=3.61)

# 2. Define concentration for a binary system (e.g., Cu-Au)
conc = Concentration(basis_elements=[["Cu", "Au"]])

# 3. Define settings for the cluster expansion
settings = Settings(
    primitive_structure=prim,
    supercell=[2, 2, 2], # Supercell dimensions for mapping
    concentrations=[conc],
    max_cluster_dia=[3.0, 4.0, 5.0] # Max diameter for 2-body, 3-body, 4-body clusters
)

# 4. Initialize the Cluster Expansion Bulk object
ce_bulk = CEBulk(settings, verbose=False)

print(f"CEBulk object initialized for {ce_bulk.name}")
# Further steps involve fitting and predicting properties.

view raw JSON →