question about the integrated el-ph coupling constant (function of frequency)

Theory Electron-phonon coupling
1

Dear All,

How is the el-ph coupling as a function of frequency (lamb(w)) calculated manually? Let us say we have how the a2F varies with frequency and we want to calculate the lamb(w) at w=w0. Is it simply the sum of 2*a2F(w)/w up to w=w0 divided by the number of frequency points up to w0?
Does it work that way?

regards

2

Hi eliephys78,

It is based on the eq. (206) of
https://doi.org/10.1103/RevModPhys.89.015003

You can see the implementation in the code;
https://gitlab.com/QEF/q-e/-/blob/develop/EPW/src/supercond.f90#L417

The integration limit is 10% above the maximum phonon frequency (see below in code)
https://gitlab.com/QEF/q-e/-/blob/develop/EPW/src/io_eliashberg.f90#L602

Best,
Hari Paudyal

3

Dear Hari,

Thanks for the references. I will have a look.

Regards