import numpy as np
import phonopy

fname = 'phonopy_params.yaml'
phonon=phonopy.load(force_sets_filename="FORCE_SETS",
#born_filename="./BORN",
#born_filename=None,
unitcell_filename="POSCAR-unitcell",supercell_matrix=np.eye(3)*3 )
phonon.save(settings={'force_constants': True})

