pm-phonons-via-irr-derivatives

The phonon frequencies are computed from the irreducible derivatives. Various different levels of output are provided.

The following tags are required:

  1. point_group
  2. lattice_vectors
  3. basis_atoms
  4. quadratic_irr_derivatives

If there are complex irreducible derivatives, the imaginary part must be provided by the tag quadratic_irr_derivatives_imaginary. The code will print out a summary of the irreducible derivatives with varying levels of verbosity.

$ pm-phonons-via-irr-derivatives -i input.yaml --print-summary --verbosity long

There are several levels of verbosity that can be seen via tab completion.


Last modified July 18, 2025: i (d991506)