ANNNI Stacking Faults¶

ANNNIStackingFaultAnalyzer ¶

ANNNIStackingFaultAnalyzer(
    calculator: BaseCalculator | None = None,
    annni_transformation: ANNNIStackingFaultTransformation
    | None = None,
)

A class used to calculate intrinsic and extrinsic stacking fault energies using the ANNNI model.

The ANNNIStackingFaultAnalyzer class compares the potential energies of FCC, HCP, and DHCP structures to compute the intrinsic and extrinsic stacking fault energies (ISFE and ESFE) per the second-order ANNNI formulae.

Initializes the ANNNIStackingFaultAnalyzer object.

Parameters:

Name	Type	Description	Default
`calculator`	`BaseCalculator \| None`	The calculator object used for relaxation and potential energy calculations.	`None`
`annni_transformation`	`ANNNIStackingFaultTransformation \| None`	The transformation object used to generate stacking fault structures. If not provided, a default instance is initialized.	`None`

calculate ¶

calculate(
    composition: Composition | str,
) -> dict[str, float]

Calculates intrinsic and extrinsic stacking fault energies (ISFE and ESFE) using the second-order ANNNI formulae.

The energy differences between FCC, HCP, and DHCP structures are normalized by the area of the FCC unit cell.

Parameters:

Name	Type	Description	Default
`composition`	`Composition \| str`	The composition of the supercell, either as a `Composition` object or as a string.	required

Returns:

Type	Description
`dict[str, float]`	dict[str, float]: Dictionary with keys: - `isfe`: Intrinsic stacking fault energy (eV/A^2). - `esfe`: Extrinsic stacking fault energy (eV/A^2).

Raises:

Type	Description
`ValueError`	If the calculator object does not have the 'energy' property implemented.

annni_transformation ¶

annni_transformation() -> ANNNIStackingFaultTransformation

Returns the ANNNI stacking fault transformation object used to generate stacking fault structures.

Returns:

Name	Type	Description
`ANNNIStackingFaultTransformation`	`ANNNIStackingFaultTransformation`	The transformation object used to generate stacking fault structures.