EPW Forum

Dear All,

Is it possible to calculate the change in phonon frequency
due to electron-phonon interaction by calculating the
real part of the phonon self energy within EPW ?

Thanks in advance for any reply.

Best regards,
Koushik

Koushik Pal
Graduate student
JNCASR, Bangalore
India

Dear Koushik,

You can look at the routine EPW/src/selfen_phon.f90

You can change the weight to

weight = wkf (ikk) * (wgkk - wgkq) * &
REAL ( cone / ( ekq - ekk - wq - ci * degaussw0 ) )

One has to be careful with the convergence when looking at the real part of the self-energy.

Usually such quantity will converge slowly with k-point, q-point and number of bands (for the el-ph matrix elements g2).

Best,

Samuel

Dear Dr. Ponce,

Thank you very much for your reply.

Best,
Koushik

Koushik Pal
JNCASR, Bangalore
India