phono3py-load command

After phono3py v2.3.2, phono3py-load command is installed. This behaves similarly to phono3py.load (phono3py.load) in the phono3py python module. The main aim of introducing this command is to provide uniform usage over many different force calculators. Once phono3py_disp.yaml is created, the following operations will be the same using this command.

The following default behaviours are different from that of those of phono3py command:

1. phono3py_xxx.yaml type file is always necessary in either of two ways:

   • phono3py_xxx.yaml type file is given as the first argument of the command.

   • phono3py_xxx.yaml type file is put in the current directory with one of the default filenames of phono3py_params.yaml, phono3py_disp.yaml, phono3py.yaml. The searching preference order is phono3py_params.yaml > phono3py_disp.yaml > phono3py.yaml.

2. -c option (read crystal structure) does not exist.

3. -d option (create displacements) does not exist.

4. Use of command options is recommended, but phono3py configuration file can be read through --config option.

5. If parameters for non-analytical term correction (NAC) are found, NAC is automatically enabled. This can be disabled by --nonac option.

6. When force constants are calculated from displacements and forces dataset, force constants are automatically symmetrized. To disable this, --no-sym-fc option is used.

7. -o option works differently from phono3py command. This option requires one argument of string. The string is used as the output yaml filename that replaces the default output yaml filename of phono3py.yaml.