phono3py command

phono3py command#

The phono3py command runs the phonon and thermal-conductivity calculation step of the workflow. It reads a phono3py.yaml-like file, constructs the phonon and ph-ph interaction, and computes the requested property (thermal conductivity, imaginary self energy, joint DOS, …).

To prepare displacements and to collect calculator results into FORCES_FC3 / FORCES_FC2 / FORCE_SETS files use phono3py-init command.

Example#

In the NaCl example for the VASP calculator,

% phono3py-init -d --dim 2 2 2 --dim-fc2 2 2 2 -c POSCAR-unitcell
% phono3py-init --cf3 disp-{00001..00146}/vasprun.xml
% phono3py-init --cf2 disp_fc2-{00001..00002}/vasprun.xml

After this, run the thermal-conductivity calculation as the post-process:

% phono3py --br --ts 300 --mesh 19 19 19

phono3py reads phono3py_disp.yaml (or phono3py.yaml) automatically when the file is present in the current directory. It can also be given as the first argument; the file can be compressed (xz, lzma, gz, bz2).

% phono3py phono3py_params.yaml.xz --br --ts 300 --mesh 19 19 19

Behaviour#

  • phono3py_xxx.yaml-like file is always required, provided in either of two ways:

    1. as the first argument of the command, or

    2. found in the current directory as phono3py_disp.yaml or phono3py.yaml (phono3py_disp.yaml takes precedence).

  • The -c option (read crystal structure separately) does not exist — the crystal structure is read from the yaml file.

  • A phono3py configuration file (Use of configuration file) can be read through --config option.

  • If parameters for non-analytical term correction (NAC) are found, NAC is automatically enabled. Use --nonac to disable.

  • When force constants are calculated from displacements and forces dataset, force constants are automatically symmetrized. Use --no-sym-fc to opt out.

  • -o takes one argument: the output yaml filename that replaces the default phono3py.yaml.

Relation to phono3py-load#

phono3py-load is the historical name of this command and is kept as a deprecated alias. It emits a warning and otherwise behaves identically to phono3py. Use phono3py in new scripts.