[Phonopy-users] Harmonic force constants calculation with QE interface

[Armin T. <arm...@gm...>]

Hello,

I am a new user of phonopy. I am trying to find the force constant matrix
for a system using phonopy and my interface is quantum espresso. I will
then use that force constant matrix for other packages such as ShengBTE or
Hiphive. I have 2 questions about phonon calculations and harmonic force
constants:

1- Based on the instruction explained here
<https://atztogo.github.io/phonopy/qe.html> for NaCl, I think I can only
get "FORCE_SETS" using QE as the interface. I was wondering what is the
difference between  FORCE_SETS  and FORCE_CONSTANTS, and how can I
obtain FORCE_CONSTANTS
using phonopy and QE interface.

2- What is the difference between " --pwscf " tag and "--qe"  tag when
dealing with phonon calculation with quantum espresso interface. I noticed
that in the phonopy examples, --pwscf is used for Si while --qe is used for
NaCl.



Thanks,

Armin