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

Posted: Tue May 11, 2021 7:37 pm
by eliephys78
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

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

Posted: Thu May 13, 2021 1:05 pm
by hpaudya1
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/devel ... d.f90#L417

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

Best,
Hari Paudyal

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

Posted: Thu May 13, 2021 7:44 pm
by eliephys78
Dear Hari,

Thanks for the references. I will have a look.

Regards