class matlantis_features.features.phonon.force_constant.FastPhonons(calculator: Calculator, supercell: Tuple[int, int, int], delta: float = 0.1, method: str = ‘frederiksen’, direction: str = ‘central’, symmetrize: int = 3, acoustic: bool = True, use_symmetry: bool = False, cutoff: Optional[float] = None, show_progress_bar: bool = False, tqdm_options: Optional[Dict[str, Any]] = None, show_logger: bool = False)#

Bases: object

Class for calculating force constant using the finite displacement method.

Methods

__init__(calculator, supercell[, delta, …])

Initialize an instance.

run(atoms)

Runs the force constant calculation.
__init__(calculator: Calculator, supercell: Tuple[int, int, int], delta: float = 0.1, method: str = ‘frederiksen’, direction: str = ‘central’, symmetrize: int = 3, acoustic: bool = True, use_symmetry: bool = False, cutoff: Optional[float] = None, show_progress_bar: bool = False, tqdm_options: Optional[Dict[str, Any]] = None, show_logger: bool = False)#

Initialize an instance.

Parameters

  • calculator (Calculator) – The calculator to estimate energy and force.

  • supercell (tuple[int, int, int]) – The number of repetitions of input structure.

  • delta (float, optional) – The distance of finite displacment. Defaults to 0.1.

  • method (str, optional) – The method to calculate force constant. Defaults to
    ‘frederiksen’.

  • direction (str, optional) – How the displacement is found. Defaults to ‘central’.

  • symmetrize (int, optional) – The number of interactions to symmetrize the force
    constant. Defaults to 3.

  • acoustic (bool, optional) – Restores the acoustic sum rule of the force constant.
    Defaults to True.

  • use_symmetry (bool) – If True, the symmetry of input structure will be used to reduce the
    number of force estimations. Defaults to False.

  • cutoff (float or None, optional) – The corresponding elements in the force constant is
    set to 0 if the interatomic distance between atoms is larger than cutoff. Defaults
    to None.

  • show_progress_bar (bool, optional) – Show progress bar. Defaults to False.

  • tqdm_options (dict[str, Any] or None, optional) – Options for tqdm.

  • show_logger (bool, optional) – Show log information. Defaults to False.

run(atoms: Union[MatlantisAtoms, Atoms]) → ndarray#

Runs the force constant calculation.

Parameters

atoms (MatlantisAtoms or ASEAtoms) – The input structure.

Returns

The force constant

Return type

np.ndarray