EPW Forum

Dear developers and Experts, Is it possible to collect/extract the dV_scf/du term as shown in the picture attached using QE/EPW? This is a formula for calculating the Born effective charge. I am sure this data (dV_scf) is stored somewhere (most probably in the binary files *.dvscf). If someone knows ...

Dear Xiaozha,

It is helpful, yes.
Thank you,

Dear experts,

Is it possible to calculate the electron-phonon matrix elements (g) along some kpath and not on a grid?
Can I give any random k point and EPW calculates the g for the chosen q and k?

Thanks,
Shubham

Okay I found the issue. It was fsthick which was creating the problem.

Could it be because of small negative frequency?
Furthermore, there are six bands in my wannier basis, why the el-ph elements are calculated for the 3rd band only?

Thanks,
Shubham

Dear all, I am trying to calculate the electron-phonon matrix elements |g| using EPW and I am getting all the elements to be zero. Is there any specific reason the g's are zero. There should be any non zero value, however small it is? I am attaching my input file (second step), and in the epw.out ...

Dear Shashi, Thank you so much for the tutorials. I also found Lihm's slides there, which are really helpful. Moreover, I wanted to know that if the data stored in the dvscf files is in the momentum space (q) or the real space(r)? After, doing some search I found it is stored in the q space, and ...

Dear experts, developers and users, I want to extract data stored in the binary files named `prefix.dvscf_q*`, or w_pot files (dV_scf in real space), which can be used to calculate electron-phonon matrix elements. Is there any way I can read the data stored in those binary files, and/or know the ...

Dear experts, I am trying to calculate momentum dependent electron-phonon coupling (EPC) using EPW code, and I came across with the website of EPW documentation https://docs.epw-code.org/doc/Electron-phononCoupling.html, where EPC it is shown how gkk is calculated using dV_scf. Now from the DFT ...

Hi Shashi,
Could you please send me the documentation for EPW, of the corrected formula implemented in EPW? I recently used that formula in one of my paper. A manual in a short page would be enough and helpful.

Thanks,
Shubham