I am using
fix phonon in LAMMPS to get the phonon dispersion relation, but this requires a post-processing code that takes the generated binary file and produces the phonon dispersion relation. This code is called
phana and I am having trouble compiling it. Is there an alternative tool that can read the binary file generated by
fix phonon and produce the phonon dispersion relation? Can
PhonoPy do that?
I am using
I was able to compile the
phana code but
fix phonon just gave a peak around zero. I raised an issue on the GitHub repository and it is still open until the writing of this answer. Based on my experience,
fix phonon is not to be trusted.
Instead, I used a tool called PhonoLAMMPS to get the forces calculated by LAMMPS in a format readable by Phonopy, and then used Phonopy to get the phonon band structure and phonon density of states (DOS) at 0 K.
The know-how can be found in the examples of both codes. Just follow the links.
The way to get this information at finite temperatures is handled by a code called DynaPhoPy, but it doesn't calculate the phonon DOS directly, just the power spectrum, which is an approximation to the phonon DOS that is very sensitive to the supercell size.