euphonic.data.bands module

class euphonic.data.bands.BandsData(seedname, model='CASTEP', path='')

Bases: euphonic.data.data.Data

A class to read and store electronic data from model (e.g. CASTEP) output files

seedname

Seedname specifying file(s) to read from

Type:str
model

Records what model the data came from

Type:str
n_qpts

Number of k-points

Type:int
n_spins

Number of spin components

Type:int
n_branches

Number of electronic dispersion branches

Type:int
fermi

The Fermi energy/energies. Default units eV

Type:(n_spins,) float ndarray
cell_vec

The unit cell vectors. Default units Angstroms

Type:(3, 3) float ndarray
recip_vec

The reciprocal lattice vectors. Default units inverse Angstroms

Type:(3, 3) float ndarray
qpts

K-point coordinates

Type:(n_qpts, 3) float ndarray
weights

The weight for each k-point

Type:(n_qpts,) float ndarray
freqs

Band frequencies, ordered according to increasing k-point number. Default units eV

Type:(n_qpts, 3*n_ions) float ndarray
freq_down

Spin down band frequencies, ordered according to increasing k-point number. Can be empty if there are no spin down frequencies present. Default units eV

Type:(n_qpts, 3*n_ions) float ndarray
__init__(seedname, model='CASTEP', path='')

” Calls functions to read the correct file(s) and sets BandsData attributes

Parameters:
  • seedname (str) – Seedname of file(s) to read
  • model ({'CASTEP'}, optional, default 'CASTEP') – Which model has been used. e.g. if seedname = ‘Fe’ and model=’CASTEP’, the ‘Fe.bands’ file will be read
  • path (str, optional) – Path to dir containing the file(s), if in another directory
calculate_dos(dos_bins, gwidth, lorentz=False, weights=None)

Calculates a density of states with fixed width Gaussian/Lorentzian broadening. Extends the Data.calculate_dos function and has the same input parameters, but additionally calculates DOS for spin down frequencies

Parameters:
  • dos_bins ((n_ebins + 1,) float ndarray) – The energy bin edges to use for calculating the DOS, in the same units as freqs
  • gwidth (float) – FWHM of Gaussian/Lorentzian for broadening the DOS bins, in the same units as freqs. Set to 0 if no broadening is desired
  • lorentz (boolean, optional) – Whether to use a Lorentzian or Gaussian broadening function. Default: False
  • weights ((n_qpts, n_branches) float ndarray, optional) – The weights to use for each q-points and branch. If unspecified, uses the q-point weights stored in the Data object
Returns:

  • dos ((n_ebins,) float ndarray) – The spin up density of states for each bin
  • dos_down ((n_ebins,) float ndarray) – The spin down density of states for each bin
cell_vec
fermi
freq_down
freqs
recip_vec