EPW Forum

Dear EPW Users, On the QE Github page, it states that for QE-6.8 * electron-phonon calculation in the non-colinear/spinorbit case is broken Does this refer to electron-phonon calculation with the EPW code? I am asking this because electron-phonon calculation can also be done with the Phonon code. I ...

Dear H. Lee,

The lines are from epw.in in the diamond example that comes with the latest QE (q-e-qe-6.7MaX-Release).

Hopefully one of the developers can help.

Thanks,
Vahid

Dear EPW Community, I have installed the latest QE/EPW and tried the diamond example with the following input file for EPW: -- &inputepw prefix = 'diam' amass(1) = 12.01078 outdir = './' iverbosity = 0 elph = .true. epbwrite = .true. epbread = .false. epwwrite = .true. epwread = .false. nbndsub = 4 ...

Dear EPW community, The above paper by Dr. Poncé and Prof. Giustino in Nano Letters, 2020, uses a pre release version of EPW. Has this version been released? They use only one k/q point along the vacuum. Could their results be obtained by the latest version of EPW? Any clarification on this question...

Dear EPW users, On this thread, it is stated that "the current version of EPW doesn't support the 2D case". I am assuming that this is for polar materials. What about non-polar 2D materials such as graphene. Does EPW support non-polar 2D materials? Or should they be still treated as 3D with a few k/...

Dear EPW Community, In the Hands-on session on resistivity and mobility with EPW, the resistivity of Pb is calculated using the Ziman formula. Are there any reasons for not using BTE instead of Ziman formula given that Ziman formula is an approximation to BTE? Thank you, Vahid Vahid Askarpour Depart...

Dear Carla,

Thank you for this clarification. I need to hack the ph.x code to remove the polar term. Simply setting epsil=.false. in the phonon calculation is not apparently enough.

Best,
Vahid

Dear EPW Users, I have compiled the version of EPW (qe-6.2.2) used in the 2018 School including the 4 files for EPC calculation for semiconductors. In the Wed. 4 session, the g matrix is calculated for SiC using epw.x and ph.x (from an earlier session). The two results agree. In EPW calculation, pol...

To add to Roxana's comments, your output shows that your PSP is norm conserving but your ecutrho is 8*ecutwfc instead of 4*ecutwfc.

Cheers,
Vahid

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

I see two issues: 1. mpirun -np 4 epw.x -npool 4 < epw.in > epw.out is fine but for the preliminary scf and nscf calculations, the -npool 4 is missing. Maybe this is not required in the latest version of EPW. 2. The ONCV PSPs are generally Hamman's norm conserving PSPs. Did you generate US PSPs? If ...