Formation Energy¶

FormationEnergyAnalyzer ¶

FormationEnergyAnalyzer(
    calculator: BaseCalculator | None = None,
    formation_energy_transformation: FormationEnergyTransformation
    | None = None,
)

A class used to calculate the formation energy of materials.

The FormationEnergyAnalyzer class computes the formation energy of a material from its composition and structure.

Initializes the FormationEnergyAnalyzer object.

Parameters:

Name	Type	Description	Default
`calculator`	`BaseCalculator \| None`	The calculator object used for energy calculations.	`None`
`formation_energy_transformation`	`FormationEnergyTransformation`	The transformation object used to generate structures required for the calculation of formation energies.	`None`

calculate ¶

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

Calculates the formation energy of the given structure.

For elemental references, each element's known experimental ground-state structure (see FormationEnergyTransformation) is relaxed with the same calculator. For the few elements whose ground state can't be constructed directly, several candidate crystal structures are relaxed instead and the lowest energy per atom is used. Each element's reference energy is cached on this analyzer instance, so calling calculate() again (even on a different structure) reuses it instead of relaxing it again; construct a new analyzer to force fresh relaxations.

Parameters:

Name	Type	Description	Default
`structure`	`Atoms \| Structure`	The structure for which the formation energy is calculated.	required
`is_relaxed`	`bool`	If `True`, the structure is assumed to be already relaxed and only a single-point energy calculation is performed. Defaults to `False`.	`False`

Returns:

Type	Description
`dict[str, float \| dict[str, dict[str, float \| bool \| Structure]]]`	dict[str, float]: Dictionary with keys: - `formation_energy`: Formation energy per atom (eV/atom). - `elemental_references`: Per-element dict of `{"structure": Structure, "energy_per_atom": float, "is_guessed": bool}`, where `is_guessed` is `True` if the element has no known experimental ground state and a guessed high-symmetry candidate was used instead.

formation_energy_transformation ¶

formation_energy_transformation() -> (
    FormationEnergyTransformation
)

Returns the transformation object used to apply distortions.

Returns:

Name	Type	Description
`FormationEnergyTransformation`	`FormationEnergyTransformation`	The transformation object used to generate structures.