Bug in load_phonopy function in Phonons.py – incorrect handling of dynamical matrices #113
Description
Hi,
I noticed that the load_phonopy function in Phonons.py does not properly load and save the dynamical matrices.
Specifically, I identified three issues:
The FORCE_CONSTANTS file loaded via cellconstructor does not correctly assign the force constants to the respective atoms.
The standard force constants in phonopy are stored in eV/Ų, but cellconstructor expects them in Ry/Bohr², leading to unit inconsistencies.
The alat parameter is not properly initialized, resulting in incorrect vector scaling.
I’ve implemented a possible fix addressing all three points:
Adjusted the code to correctly map the full force constants as output by phonopy.
Applied proper unit conversion to Ry/Bohr².
Correctly initialized the alat parameter.
I’ve attached a modified version of the load_phonopy function for your review if you deem appropriate.