euphonic-dos

The euphonic-dos program can be used to plot density of states, partial density of states, and/or neutron-weighted density of states. It can use pre-calculated frequencies, or use force constants to generate frequencies and DOS over a Monkhorst-Pack grid. For example, to plot DOS from a CASTEP .phonon file in units of 1/cm, run:

euphonic-dos --energy-unit 1/cm quartz-554-grid.phonon

Or, to plot coherent neutron-weighted DOS from CASTEP force constants in a .castep_bin file on a 15x15x12 grid with broadening, run:

euphonic-dos --weighting coherent-dos --grid 15 15 12 --energy-broadening 1.5 quartz.castep_bin

To see all the command line options, run:

euphonic-dos -h

You can also see the available command line options below

Command Line Options

Plots a DOS from the file provided. If a force constants file is provided, a DOS is generated on the Monkhorst-Pack grid specified by the grid (or grid-spacing) argument.

usage: euphonic-dos [-h] [--asr [{reciprocal,realspace}]]
                    [--dipole-parameter DIPOLE_PARAMETER]
                    [--use-c | --disable-c] [--n-threads N_THREADS]
                    [--pdos [PDOS [PDOS ...]]]
                    [--weighting {dos,coherent-dos,incoherent-dos,coherent-plus-incoherent-dos}]
                    [--grid GRID GRID GRID | --grid-spacing GRID_SPACING]
                    [-s SAVE_TO] [--title TITLE] [--x-label X_LABEL]
                    [--y-label Y_LABEL] [--e-min E_MIN] [--e-max E_MAX]
                    [--energy-unit ENERGY_UNIT] [--ebins EBINS] [--adaptive]
                    [--energy-broadening ENERGY_BROADENING]
                    [--shape [{gauss,lorentz}]] [--length-unit LENGTH_UNIT]
                    filename

File I/O arguments

filename

Phonon data file. This should contain force constants or phonon mode data. Force constants formats: .yaml, force_constants.hdf5 (Phonopy); .castep_bin , .check (Castep); .json (Euphonic). Phonon mode data formats: {band,qpoints,mesh}.{hdf5,yaml} (Phonopy); .phonon (Castep); .json (Euphonic)

q-point sampling arguments

--grid

Defines a Monkhorst-Pack grid.

--grid-spacing

q-point spacing of Monkhorst-Pack grid.

Default: 0.1

--length-unit

Length units; these will be inverted to obtain units of distance between q-points (e.g. “bohr” for bohr^-1).

Default: “angstrom”

energy/frequency arguments

--e-min

Energy range minimum in ENERGY_UNIT

--e-max

Energy range maximum in ENERGY_UNIT

--energy-unit, -u

Energy units

Default: “meV”

--ebins

Number of energy bins

Default: 200

--adaptive

Use adaptive broadening on the energy axis to broaden based on phonon mode widths, rather than using fixed width broadening

Default: False

--energy-broadening, --eb

If using fixed width broadening, the FWHM of broadening on energy axis in ENERGY_UNIT (no broadening if unspecified). If using adaptive broadening, this is a scale factor multiplying the mode widths (no scale factor applied if unspecified).

--shape

Possible choices: gauss, lorentz

The broadening shape

Default: “gauss”

Force constants interpolation arguments

--asr

Possible choices: reciprocal, realspace

Apply an acoustic-sum-rule (ASR) correction to the data: “realspace” applies the correction to the force constant matrix in real space. “reciprocal” applies the correction to the dynamical matrix at each q-point.

--dipole-parameter

Set the cutoff in real/reciprocal space for the dipole Ewald sum; higher values use more reciprocal terms. If tuned correctly this can result in performance improvements. See euphonic-optimise-dipole-parameter program for help on choosing a good DIPOLE_PARAMETER.

Default: 1.0

Property-calculation arguments

--pdos

Plot PDOS. With –pdos, per-species PDOS will be plotted alongside total DOS. A subset of species can also be selected by adding more arguments e.g. –pdos Si O

--weighting, -w

Possible choices: dos, coherent-dos, incoherent-dos, coherent-plus-incoherent-dos

Type of DOS to plot: DOS, coherent neutron-weighted DOS, incoherent neutron-weighted DOS or total (coherent + incoherent) neutron-weighted DOS

Default: “dos”

Plotting arguments

-s, --save-to

Save resulting plot to a file with this name

--title

Plot title

Default: “”

--x-label

Plot x-axis label

--y-label

Plot y-axis label