EPW Forum

Dear Agathyan,

For the renormalization of the velocity matrix elements, see Eq.30 in https://doi.org/10.1103/PhysRevB.62.4927.

Thanks!
Xiao

Hi, Just as to add to Sabya's point: this renormalization is performed in the case of reading an external eigenvalue. Therefore, it is mostly recommended to use that option as much as possible instead of using a scissor. If you would like use a scissor shift, one way to have EPW does the ...

Dear Agathyan, Thanks for updating! Just by eyeballing your absorption coefficient indeed seems quite close to the converged values in the PRL. If you used two different set of GW eigenvalues from two different GW calculations (12 bands and 34 bands) with different settings, naturally that ...

Dear Shubham, Yes this can be done by specifying tag filkf and filqf to provide an arbitrary set of k and/or q points: https://docs.epw-code.org/doc/Inputs.html#filkf https://docs.epw-code.org/doc/Inputs.html#filqf And using prtgkk to print the el-ph matrix elements. I would recommend checking ...

Dear Agathyan, Looking at the plot, a few potential possibilities: -First, looks very likely that with 12 bands, you are using eig_read = .true. with the provided Quasiparticle energies si.eig. Each block of that file contains quasiparticle energies to correct the DFT gap of each k-point and 12 ...

Dear Pavel, Thank you for your question! A few thoughts related to your question and discussion: For the ones that worked: -Looking at the spectra, the bump that you observed in the region between 0.4-0.5 eV seem to be caused by spin-orbit splitting. In fact, as you mentioned, if the predicted ...

Hi Pravin, Please note that the version number of EPW is not the same as the version number of Quantum Espresso. When you say 7.1, it seems that you are referring to the version of QE, and indeed QE 7.1 does not have implementation of ionized impurity scattering. The ionized impurity scattering was ...

Hi, Here the key is the following few points: -The projection that you defined (using proj) and the number of Wannier functions that you provide the code (nbndsub) needs to be matched exactly. -You need to have enough total number of bands. (your nscf combined with bands_skipped) -The number of ...

Hi, Looking at the input, it seems you provided an initial project of: proj(1)='Te:p' and proj(2)='Hf:d'. Note that this needs to match the number of Wannier functions you give the code (nbndsub). With these projections, 10 Te, and 2 Hf, I believe that gives a total of 80 electrons (40 orbitals ...

Hi, While I don't see an obvious error in your input, there are a few things I'd suggest to try: 1. Could you please check the Fermi level the code print out, and whether the energy window you see at the tail of your output does cover the conduction band states you want (looks like you are looking ...