Bain Displacement¶

BainDisplacementTransformation ¶

BainDisplacementTransformation(
    start: float = 0.89,
    stop: float = 1.5,
    step: float = 0.01,
    symprec: float = 0.01,
)

Generates a series of deformed structures along the Bain path.

Varies the c/a ratio in small steps to produce structures along the Bain transformation pathway between cubic and tetragonal phases.

Initializes the BainDisplacementTransformation object.

Parameters:

Name	Type	Description	Default
`start`	`float`	The starting displacement value for the c/a ratio. Defaults to 0.89.	`0.89`
`stop`	`float`	The stopping displacement value for the c/a ratio. Defaults to 1.5.	`1.5`
`step`	`float`	The step size for incrementing the c/a ratio. Defaults to 0.01.	`0.01`
`symprec`	`float`	Symmetry precision used to standardize the input structure to a conventional cell before deforming it. Defaults to 1e-2.	`0.01`

Raises:

Type	Description
`ValueError`	If `start` or `stop` is not positive, or if `step` is not positive.

apply_transformation ¶

apply_transformation(
    structure: Structure,
) -> dict[float, Structure]

Generate displaced structures along the Bain path.

The Bain strain is defined relative to the Cartesian x/y/z axes, so structure is first standardized to a conventional, axis-aligned cubic cell (via SpacegroupAnalyzer) before being deformed.

Parameters:

Name	Type	Description	Default
`structure`	`Structure`	The input structure to be displaced along the Bain path.	required

Returns:

Type	Description
`dict[float, Structure]`	dict[float, Structure]: The displaced structures, keyed by the corresponding c/a ratio.