EPW Forum

Dear Shudong,

I have used PBE functional with EPW. So, yes it can be used. The important thing is to be able to get correct electron/phonon band structures from EPW. And to get structural parameters that are more consistent with the experiment.

Cheers,

Vahid

You can download rel-pz.0.3.1.tgz from the following website: m. The file includes norm-conserving LDA full-relativistic pseudopotentials. Also available are the PBE counterparts. Alternatively, you can use sg15_oncv_upf_2015-10-07.tar.gz from the following website: m. The PSPs are not full ...

Hi Samuel and Carla,

I found out why the matdyn and EPW phonon dispersions did not match. In converting from meV to wavenumber, I used a factor of 0.12 whereas I should have used 0.12398. My bad!

Best,

Vahid

Hi Carla, I have not tried running GaN without SOC. I have run other polar materials without SOC and there were no discrepancies between matdyn and EPW phonon dispersion. Fo this thread, I was merely trying to run on GaN with SOC. I checked to see if the phonon dispersions are consistent but they ...

Hello,

I will try to debug the SOC part of the code. I will keep you posted as to what I find.

Best,

Vahid

Dear Samuel, The setting asr_typ=crystal (m) and lifc=.false. (m) are consistent with the lifc=true and asr_typ=simple result reported earlier. In all three cases, EPW is consistently higher than matdyn. And in all three cases, EPW dispersion is the same. I also tried asr=crystal in matdyn.in and ...

Dear Samuel, I ran the phonon dispersion with qe-6.2.1 using both the matdyn.x code and EPW-4.3.0 for GaN example case. I used 6x6x6 coarse k/q grids. The PSP is given earlier on this thread. It is a fully relativistic PSP. Tags lpolar and epsil, lspinorb and noncolin are all set to true. In the EPW ...

Dear Samuel, I printed lrigid, epsi_, and zstar_ before the IF (lrigid) section and lrigid, epsi, and zstar after the IF (lrigid) section of the readmat_shuffle2.f90. For the first q, lrigid is T and the other parameters are finite. For other q-points, lrigid is F, epsi_ and zstar_ are zero and epsi ...

Dear Samuel, I successfully installed qe-6.2 and redid all the phonon, scf, and nscf calculations with the new module. For the first q-point, I get lrigid=T and finite epsi, epsi_, zstar and zstar_ as below: Reading interatomic force constants IFC last -1.724147163949322E-003 Imposed simple ASR ...

Dear Samuel,

I was using QE-6.0. Since I had made many changes to the code, I was hoping to debug that version. However, I am in the process of installing qe-6.2 and may have to redo all the phonon calculations. I will try 6.2 version and let you know what I get.

Thanks,

Vahid