aiida_quantumespresso.data.force_constants

Sub class of Data to handle interatomic force constants produced by the Quantum ESPRESSO q2r.x code.

Module Contents

Classes

ForceConstantsData

Class to handle interatomic force constants from the Quantum ESPRESSO q2r.x code.

Functions

parse_q2r_force_constants_file(lines[, ...])

Parse the real-space interatomic force constants file from QE-Q2R.

class aiida_quantumespresso.data.force_constants.ForceConstantsData(file: str | pathlib.Path | IO, filename: str | pathlib.Path | None = None, **kwargs: Any)

Bases: aiida.orm.SinglefileData

Class to handle interatomic force constants from the Quantum ESPRESSO q2r.x code.

property number_of_species

Return the number of atom species.

Returns:

a scalar

property number_of_atoms

Return the number of atoms.

Returns:

a scalar

property cell

Return the crystal unit cell where rows are the crystal vectors.

Returns:

a 3x3 numpy.array

property atom_list

Return the list of atoms.

Returns:

a list of length-5 tuple (element name, element mass amu_ry, 3 coordinates in cartesian Angstrom)

property has_done_electric_field

Return flag to indicate if dielectric tensor and effective charges were computed.

Returns:

a boolean

property dielectric_tensor

Return the dielectric tensor matrix.

Returns:

a 3x3 tuple

property effective_charges_eu

Return the effective charges for each atom.

Returns:

a list of number_of_atoms elements, each being a 3x3 tuple

property qpoints_mesh

Return the number of q-points in each direction.

Returns:

a length-3 tuple

set_file(file, filename=None, **kwargs)

Add a file to the node, parse it and set the attributes found.

Parameters:

• file – absolute path to the file or a filelike object

• filename – specify filename to use (defaults to name of provided file).

aiida_quantumespresso.data.force_constants.parse_q2r_force_constants_file(lines, also_force_constants=False)

Parse the real-space interatomic force constants file from QE-Q2R.

Parameters:

also_force_constants – True to parse the force constants as well

Return parsed_data:

dictionary with the following keywords:

• number_of_species: number of atom species (‘ntyp’ in QE)

• number_of_atoms: number of atoms (‘nat’ in QE)

• cell: unit cell

• atom_list: list with, for each atom in the cell, a length-5 tuple of the form (element_name, mass_in_amu_ry, then 3 coordinates in cartesian & Angstroms)

• has_done_electric_field: True if dielectric constants & effective charges were computed

• dielectric_tensor: dielectric constant (3x3 matrix)

• effective_charges_eu: effective charges (ntyp x 3 x 3 matrix)

• qpoints_mesh: length-3 tuple with number of qpoints in each dimension of the reciprocal lattice

• force_constants: the real-space force constants: array with 7 indices, of the kind

  C(mi1, mi2, mi3, ji1, ji2, na1, na2) with * (mi1, mi2, mi3): the supercell dimensions * (ji1, ji2): axis of the displacement of the two atoms (from 1 to 3) * (na1, na2): atom numbers in the cell.

• warnings: a list of warnings

Return force_constants:

the real-space force constants: array with 7 indices, of the kind C(mi1, mi2, mi3, ji1, ji2, na1, na2) where: * (mi1, mi2, mi3): the supercell dimensions * (ji1, ji2): axis of the displacement of the two atoms (from 1 to 3) * (na1, na2): atom numbers in the cell.