Equation of State¶

EOSAnalyzer ¶

EOSAnalyzer(
    start: float = -0.1,
    stop: float = 0.1,
    num: int = 11,
    eos_name: Literal[
        "murnaghan",
        "birch",
        "birch_murnaghan",
        "pourier_tarantola",
        "vinet",
        "deltafactor",
        "numerical_eos",
    ] = "birch_murnaghan",
    calculator: BaseCalculator | None = None,
    eos_transformation: EOSTransformation | None = None,
)

A class used to perform Equation of State (EOS) analysis for a given structure.

Generates a series of structures with varying volumes via deformation transformations, calculates their energies, and fits the energy-volume data to an EOS (such as Birch-Murnaghan) to determine properties such as the bulk modulus.

Initializes the EOSAnalyzer object.

Parameters:

Name	Type	Description	Default
`start`	`float`	The starting strain value to apply to the structure. Defaults to -0.1.	`-0.1`
`stop`	`float`	The stopping strain value to apply to the structure. Defaults to 0.1.	`0.1`
`num`	`int`	The number of strain values to generate between the start and stop. Defaults to 11.	`11`
`eos_name`	`str`	The name of the equation of state (EOS) used for fitting. Defaults to "birch_murnaghan".	`'birch_murnaghan'`
`calculator`	`BaseCalculator \| None`	The calculator used for energy calculations.	`None`
`eos_transformation`	`EOSTransformation \| None`	The transformation used to generate deformed structures. Defaults to `EOSTransformation`.	`None`

calculate ¶

calculate(
    structure: Structure | Atoms, is_relaxed: bool = False
) -> dict[str, list | float]

Calculates the potential energies and volumes to construct the EOS for the given undeformed structure.

Applies a series of volume deformations to the input structure, calculates the potential energy of each strained structure, and fits the data to the specified equation of state (EOS).

Parameters:

Name	Type	Description	Default
`structure`	`Structure \| Atoms`	The undeformed structure to be analyzed.	required
`is_relaxed`	`bool`	Whether the structure is already relaxed. Defaults to False.	`False`

Returns:

Type	Description
`dict[str, list \| float]`	dict[str, list \| float]: Dictionary with keys: - `volumes`: Volume for each deformed structure. - `energies`: Potential energy for each deformed structure. - `e0`: Minimum energy from EOS fit. - `b0`: Bulk modulus in eV/A^3. - `b0_GPa`: Bulk modulus in GPa. - `b1`: Pressure derivative of bulk modulus. - `v0`: Equilibrium volume in A^3.

Raises:

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

eos_transformation ¶

eos_transformation() -> EOSTransformation

Returns the EOS transformation object used to generate deformed structures.

Returns:

Name	Type	Description
`EOSTransformation`	`EOSTransformation`	The transformation object used for EOS analysis.