EPW Forum

I also had this issue. I made sure to use QE v 7.2 for the scf+nscf+ph+epw calculations. The nq grid is the same between ph/EPW. I have also checked that the patterns files exist, and they appear to be of the correct format for the read_disp_pattern usage. Using QE v 7.1 rerunning all the calculatio...

Hello, From my understanding, R_e and R_p basically refer to the unit cells. So if R_e = 2, you're computing the el-ph interaction between WF n in unit cell 2, and WF m in unit cell 0 (everything is defined w.r.t. 0). The papers on EPW should explain it better. I believe for R_e and R_p there should...

Hi hlee,
Thank you. I will look into this more.

I'm not the original poster, but I'm also looking at this. QE's DFPT doesn't seem to scale well enough for large/complex systems for us, so I think I'm going to try making an interface for VASP+phonopy->EPW. I'd like your input hlee on this. You mention we'd need the dynamical matrices (can be gener...

Thank you for the feedback H. Lee, I recalled your previous advice so my question I suppose was more about the VASP-EPW interface. I will communicate with my colleagues about the difficulty.

Is there any update to this? Perhaps Wannier90's 'write_u_matrices' parameter serves this purpose?

In particular, we're looking at how feasible it could be to make an EPW-VASP interface (unless you already know of one).

Hello H. Lee, Thank you for the explanations. I appreciate your help. I definitely did not know about not needing the q-points in epw.in anymore, that's super helpful. I will disable the diago_xxx parameter then. Thanks again. I understand the documentation isn't all updated since this is the develo...

Hi hlee, I used nosym=.true. because it used to be recommended for EPW back in 2018 because PW would produce extraneous k-points that EPW didn't handle, see http://indico.ictp.it/event/8301/session/97/contribution/539/material/0/0.pdf . I assume that has been changed by now. I got rid of nosym=.true...

Hi H. Lee, I've rerun using the new pp.py to organize the phonon data, and no difference. So here's a data dump: scf.in &CONTROL title = 'DyTe3_prim' calculation = 'scf' restart_mode = 'from_scratch' pseudo_dir = '/home/adenchfield/my_pseudo' prefix = 'DyTe3' etot_conv_thr = 0.0001 forc_conv_thr = 0...

The epw_trev_paw test works fine (other than I had to manually do the pp.py part because the server's python script wanted the prefix to have 'prefix' instead of just prefix, e.g. apostrophes. I think it's a python2 vs python3 thing. PS) I think this is not related to your issue. But, as you probabl...