EPW Forum

Dear experts, by default it is possible to print the electron-phonon vertex |g| (in meV) for each q-point, k-point, i-band, j-band and modes using prtgkk. I need to evaluate g_{m,n,nu}(Re,q) = electron phonon matrix elements in the Wannier basis i.e. equation (34) e (35) of https://journals.aps.org/...

Dear experts, I am occurring in the same problem more or less for a monolayer of MoS2 I tried to use k = 21 21 7 and q = 7 7 1 and k = 16 16 2 and q = 16 16 2 but the decay files give in both cases bad behaviour when I plot decay.epmat_wanep vs Rp (i.e. 2nd and 3rd column) I reported my results and ...

Dear Zhe, the reason why I am using different PP is because I am using the one reported in this library https://www.materialscloud.org/discover/sssp/table/efficiency (which are the one tested for quantum espresso, see here https://www.materialscloud.org/discover/2dstructures/details/MoS2 ) I tried t...

Dear Zhe, Thank you for your time and reply and yes, your explanation is clear I will try to increase the q grid in the phonon calculation, hoping that this will give a better result of decay.epmat_wanep vs Rp with a 771 q-grid my result is the one reported in section Check with EPW (fig 6) in https...

Dear Zhe,
thank you for your answer, although

1) moving the Ef close to the CB gives exactly the same result as if it is close to the VB

2) Yes, it works, but I do not get the reason why (I'm sorry..)

Best regards

Sara
ETH - Zurich
PhD student

Dear Zhe, thank you for your reply. 1) using Quantum ESPRESSO with a small smearing in the nscf file, I get the value of the Fermi energy grep "Fermi" nscf_smearing.out >> the Fermi energy is -1.5849 ev 2) It is not clear to me what you meant... I reported here m what I obtained changing o...

Dear experts, I am trying to obtain the electron-phonon coupling matrix elements g(q,k) of a monolayer of MoS2 For the seek of simplicity I reported a detailed description of the inputs and of the plot here : https://paper.dropbox.com/doc/e-ph-coupling-ML-MoS2-EPW-5.1--AapH9Z046bS0GI5t3aJK2htEAQ-thd...

Dear Vahid Askarpour, Thank you for you answer! using mpirun -np 4 pw.x -npool 4 < scf.in > scf.out mpirun -np 4 pw.x -npool 4 < nscf.in > nscf.out mpirun -np 4 epw.x -npool 4 < epw.in > epw.out works! I am still having problems with the path.dat file, but it is probably just a matter of format. I'l...

Dear Experts, I am trying to compute the electron-phonon coupling matrix elements of a monolayer of MoS2 But when I try to run EPW.X I get the following error Program received signal SIGSEGV: Segmentation fault - invalid memory reference. Backtrace for this error: #0 0x2b921484b26f in ??? #1 0x2b921...

Dear Samuel, thank you for your answer and I am sorry to have to ask again your help (and that I'm mixing my questions with the ones of the other user) I do not understand : ik =2 is the second point of what? of a list? of a grid? which list/grid? I am using the following inputs from the School : Ha...