EPW Forum

Dear Mehmet: Could you make the following parts of your make.inc in QE 6.6 the same as those in QE 6.4.1? I just would like to know whether or not this issue originates from the building environments. 53c56 < IFLAGS = -I$(TOPDIR)/include -I$(TOPDIR)/FoX/finclude -I$(TOPDIR)/S3DE/iotk/include/ -I/opt...

Dear Fanchem: The reason is that as you can see below, in Wannier90, use_ws_distance = .true in default, but in EPW, use_ws = .false. in default. From parameters.F90 in Wannier90 src directory use_ws_distance = .true. call param_get_keyword('use_ws_distance', found, l_value=use_ws_distance) From epw...

Dear Fanchem: In your case, you are using "Minimal-distance replica selection method" by adding "'use_ws_distance = .true." when interpolating band structures in Wannier90 (W90). So I think that you need to add "use_ws = .true." in your epw input for consistent comparison. Also, there is something i...

Dear Mehmet: In addition to my previous message posted today: You can also skip writing epb files by adding both "epbwrite=.false." and "epbread=.false.". In most cases, epb files are not necessary since usually we restart with the electron-phonon vertex on coarse grids in Wannier representation. Ho...

Dear anyipeng: You need to additionally modify several parts in the subroutines of compute_amn and compute_mmn, etc. in PP/src/pw2wannier90.f90 . For example, IF (ionode) WRITE (iun_mmn,'(7i5)') ik, ikp, (g_kpb(ipol,ik,ib), ipol=1,3) IF (ionode) WRITE(iun_amn,'(3i5,2f18.12)') ibnd1, iw+n_proj*(ipol-...

Dear Fanchem:

In order to identify your issue, I need more information:
Could you provide your obtained band dispersions and all relevant inputs and outputs?

Sincerely,

H. Lee

Dear Mehmet: 1. Regarding the overflow error: You passed all parallel EPW tests; since they include writing prefix.epb* files, this fact means that (in general) you have no issue with writing prefix.epb* files. I don't know what this means but probably it has something to do with the size of these f...

Dear Mehmet: First, I found one suspicious thing in your old output of epw2.out as you can see below: Using q-mesh file: scf_band.kpt WARNING: q-point weigths do not add up to 1 [loadqmesh_serial] Size of q point mesh for interpolation: 297 Using k-mesh file: scf_band.kpt WARNING: k-point weigths do...

Dear Hao Zhang: Since you are using EPW v5.3, you should not use nosym=.true. in nscf.in. Please read carefully the Releases page at https://docs.epw-code.org/doc/Releases.html . Additionally, your k and q grids are not commensurate. Please modify the number of grids. Lastly, although it is not rela...

Dear Mehmet Dogan: I would simply replace the EPW folder in the QE-6.4.1 package with the one from QE-6.6, and recompile. I think that you would encounter the error in compiling since several changes of QE v6.6 were reflected in the EPW v5.3. Instead, you would try to just use the results of phonon ...