pymatgen.io.shengbte module

This module implements reading and writing of ShengBTE CONTROL files.

class Control(ngrid: list[int] | None = None, temperature: float | dict[str, float] = 300, **kwargs)

Bases: MSONable, dict

Class for reading, updating, and writing ShengBTE CONTROL files. See https://bitbucket.org/sousaw/shengbte/src/master/ for more detailed description and default values of CONTROL arguments.

Parameters:

• ngrid – Reciprocal space grid density as a list of 3 ints.

• temperature – The temperature to calculate the lattice thermal conductivity for. Can be given as a single float, or a dictionary with the keys “min”, “max”, “step”.

• **kwargs –

  Other ShengBTE parameters. Several parameters are required for ShengBTE to run - we have listed these parameters below:

  • nelements (int): number of different elements in the compound

  • natoms (int): number of atoms in the unit cell

  • lattvec (size 3x3 array): real-space lattice vectors, in units of lfactor

  • lfactor (float): unit of measurement for lattice vectors (nm).

    I.e., set to 0.1 if lattvec given in Angstrom.

  • types (size natom list): a vector of natom integers, ranging from 1 to nelements, assigning an element to each atom in the system

  • elements (size natom list): a vector of element names

  • positions (size natomx3 array): atomic positions in lattice coordinates

  • scell (size 3 list): supercell sizes along each crystal axis used for the 2nd-order force constant calculation

allocations_keys = ['nelements', 'natoms', 'ngrid', 'norientations']

as_dict()

Returns: MSONable dict

crystal_keys = ['lfactor', 'lattvec', 'types', 'elements', 'positions', 'masses', 'gfactors', 'epsilon', 'born', 'scell', 'orientations']

flags_keys = ['nonanalytic', 'convergence', 'isotopes', 'autoisotopes', 'nanowires', 'onlyharmonic', 'espresso']

classmethod from_dict(control_dict: dict)

Write a CONTROL file from a Python dictionary. Description and default parameters can be found at https://bitbucket.org/sousaw/shengbte/src/master/. Note some parameters are mandatory. Optional parameters default here to None and will not be written to file.

Parameters:

control_dict – A Python dictionary of ShengBTE input parameters.

classmethod from_file(filepath: str)

Read a CONTROL namelist file and output a ‘Control’ object

Parameters:

filepath – Path of the CONTROL file.

Returns:

‘Control’ object with parameters instantiated.

classmethod from_structure(structure: Structure, reciprocal_density: int | None = 50000, **kwargs)

Get a ShengBTE control object from a structure.

Parameters:

• structure – A structure object.

• reciprocal_density – If not None, the q-point grid (“ngrid”) will be set using this density.

• kwargs – Additional options to be passed to the Control constructor. See the docstring of the __init__ method for more details

Returns:

A ShengBTE control object.

get_structure() → Structure

Get a pymatgen Structure from a ShengBTE control object.

The control object must have the “lattvec”, “types”, “elements”, and “positions” settings otherwise an error will be thrown.

Returns:

The structure.

params_keys = ['t', 't_min', 't_max', 't_step', 'omega_max', 'scalebroad', 'rmin', 'rmax', 'dr', 'maxiter', 'nticks', 'eps']

required_params = ['nelements', 'natoms', 'ngrid', 'lattvec', 'types', 'elements', 'positions', 'scell']

to_file(filename: str = 'CONTROL')

Writes ShengBTE CONTROL file from ‘Control’ object

Parameters:

filename – A file name.