EPW Forum

Dear adenchfi: Is the slow part you mentioned in this part of pw2wan2epw.f90? The part you mentioned could be slow, but the main bottleneck is below: IF (noncolin) THEN CALL ZGEQP3(numbands, 2 * nrtot, TRANSPOSE(CONJG(psi_gamma)), numbands, & piv, qr_tau, cwork, lcwork, rwork, info) ELSE CALL ZGEQP3...

Dear adenchfi: Good to know that your calculations work. Well, currently the QR factorization with column pivoting, an essential part of the SCDM method, is not parallelized both in Wannier90 and EPW; thus, for large configurations, this step could be slow. Lastly, as you probably know, the bug in t...

Dear adenchfi: I have been working on finding or generating norm-conserving (NC) pseudopotentials the past couple days using atomic/ld1.x exactly because of your recommendation, and let me tell you, for some rare-earth elements (in my case La, Ce, through Dy) it is very difficult and doesn't seem to...

Dear adenchfi: I reproduced your problem and found a minor bug in the subroutine of compute_mmn_para() in EPW/src/pw2wan2epw.f90 ; this error is due to the double allocation of bec%k. The temporary fix is as follows: (1) Find the part below in the subroutine of compute_mmn_para() ! ! USPP ! IF (any_...

Dear adenchfi: Personally, I would suggest you to use norm-conserving pseudopotentials (PPs) for the SCDM method even though officially the paper (https://arxiv.org/abs/1909.00433) mentions no restriction in choice of PPs (See Appendix A in this paper). Well, could you confirm that you are using the...

Dear adenchfi: In case that you excluded some bands in the Wannierization step, the recent development version of EPW (downloaded at https://gitlab.com/QEF/q-e) excludes these bands also in the step of evaluation of electron-phonon matrix elements on coarse grids, leading to the shorter computing ti...

Dear all:

I am sorry, but there was a typo in my previous post:
(X) "bands_skipped = 'exclude_bands = 1-5"
(O) bands_skipped = 'exclude_bands = 1-5'

Sincerely,

H. Lee

Dear Gautam Sharma Monty: >Could it be due to directory of phonon-dvscf files computed using qe-6.4. I didn't check it, but you can check it yourself by performing test calculations for a simple system, for example, Pb with spin-orbit coupling. >Do I need to compute the phonons again with QE-6.5? I ...

Dear Sungwoo Lee: Are you referring to the EPW v5.2 included in the official Quantum Espresso (QE) v6.5 which can be downloaded at https://github.com/QEF/q-e/releases or https://gitlab.com/QEF/q-e/-/tags ? Or, are you referring to the development version of EPW which can be downloaded at https://git...

Dear Gautam Sharma Monty: Regarding the xml issue: Did you try the EPW included in QE v6.5 or the recent version of EPW? I didn't implement it, but I think that this issue is addressed by calling the subroutine of check_is_xml_file. Please check the subroutines of read_ifc in io_epw.f90 and dynmat_a...