EPW Forum

The wannier spreads seem too large. I find it easier to first do the Wannier analysis with the Wannier code before running EPW.

This, however, may not be the cause of the crash.

Cheers,

Vahid

Vahid Askarpour
Department of Physics and Atmospheric Science
Dalhousie University,
Halifax, NS, Canada

In the latest EPW version, you only need to specify the three coordinates and can skip the weight. If you are using an older version and need wq, you can do a separate self-consistent run with that grid and QE will print the weights in the output. Cheers, Vahid Vahid Askarpour Department of Physics ...

I once had a similar issue. One reason was that for norm-conserving PSP, ecutrho=4*ecutwfc. I chose ecutrho larger than 4*ecutwfc and EPW got stuck. Did you change ecutrho after you switched to norm-conserving PSP? Cheers, Vahid Vahid Askarpour Department of Physics and Atmospheric Science Dalhousie...

I would check a few things: 1. Are the masses of the two atoms consistent in all the QE and EPW runs? 2. Is the ifc generated by q2r.x converged w.r.t the q-grid? In other words, if you increase the q-grid in PHONON calculation, will matdyn.x result in the same phonon dispersion? This would have not...

The fsthick looks too large as well.Perhaps lowering it to the desired energy range might help.

Cheers,

Vahid

Vahid Askarpour
Department of Physics and Atmospheric Science
Dalhousie University,
Halifax, NS, Canada

Dear Fanchem, If you have the latest QE package (6.2.1), you can use the EPW tag lifc=.true. to use the ifc generated by q2r.x directly with EPW. Please see the documentation for lifc to see how it is done. Cheers, Vahid Vahid Askarpour Department of Physics and Atmospheric Science Dalhousie Univers...

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-relativi...

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 ap...