I want to calculate electron-phonon matrix using EPW in bloch basis, I have noticed using input 'prtgkk' EPW can print the absolute value of electron-phonon matrix. What should I do ,if I want a complex value of electron-phonon matrix? (Maybe some scripts need to be modified?) .I found print_gkk(iq) in printing.f90 is responsible for the output of electron phonon matrix, but I don't konw the correct way to modify it.

I also noticed that electron-phonon matrix is gauge dependent.Are there any ways to obtain complex value of electron-phonon matrix which is in consistent gauge with nscf result?

## electron-phonon matrix

**Moderator:** stiwari