Search found 308 matches

by hlee
Wed Oct 13, 2021 5:32 pm
Forum: General discussion
Topic: " matrix is singular" in 2D materials using EPW
Replies: 3
Views: 80

Re: " matrix is singular" in 2D materials using EPW

Dear guodonglin:

You are using the old version of EPW v.4.0.0 and it is difficult for me to keep track of the origin of your issue.
Could you try to use the recent version of EPW (v5.4) and confirm that you still encounter the issue?

Sincerely,

H. Lee
by hlee
Tue Oct 12, 2021 6:59 pm
Forum: General discussion
Topic: " matrix is singular" in 2D materials using EPW
Replies: 3
Views: 80

Re: " matrix is singular" in 2D materials using EPW

Dear guodonglin:

Could you show me the full outputs of nscf.out and epw.out with the inputs of nscf.in and epw.in?

Sincerely,

H. Lee
by hlee
Thu Oct 07, 2021 5:05 pm
Forum: Running the code
Topic: Error in anisotropic calculation
Replies: 11
Views: 264

Re: Error in anisotropic calculation

Dear Mehmet: You need to find the origin in the following ways: First, you need to print out the values of relevant variables on each MPI task. To do this, please proceed as follows: (1) Change the line of "MANUAL_DFLAGS =" in make.inc in the QE root directory with that of "MANUAL_DFLAGS = -DDEBUG"....
by hlee
Thu Oct 07, 2021 4:26 pm
Forum: General discussion
Topic: What is the bare phonon frequency in EPW
Replies: 6
Views: 201

Re: What is the bare phonon frequency in EPW

Dear Zishen: It seems that the code (QE or EPW) uses renormalized phonon frequency in the calculation. Yes, you are right. After reading the paper titled "Ab initio downfolding for electron-phonon-coupled systems: Constrained density-functional perturbation theory" at http://dx.doi.org/10.1103/PhysR...
by hlee
Mon Oct 04, 2021 4:13 pm
Forum: Running the code
Topic: Calculation gets frozen during/after wannierization stage
Replies: 3
Views: 118

Re: Calculation gets frozen during/after wannierization stage

Dear Mikhail: Your issue is strange to me. In your case, two steps, disentanglement and Wannierization should be done in library call to Wannier90 (W90). In the case (I), the calculation is still running in W90; so basically this issue is related to W90. In the case (II), you didn't show me the outp...
by hlee
Mon Oct 04, 2021 3:59 pm
Forum: Running the code
Topic: Plotting wannier bands immediately after wannierization
Replies: 1
Views: 72

Re: Plotting wannier bands immediately after wannierization

Dear Mikhail: The simplest method is to plot Wannier-interpolated bands after Wannierization in library call to Wannier90. You just need to add relevant inputs using the input flag of wdata to epw.in . Please check the following example: (From QE-path/test-suite/epw_metal/epw1.in) wdata(1) = 'bands_...
by hlee
Fri Oct 01, 2021 7:41 pm
Forum: General discussion
Topic: What is the bare phonon frequency in EPW
Replies: 6
Views: 201

Re: What is the bare phonon frequency in EPW

Dear Zishen: I think that we might say something different. The only thing I can tell you is that when evaluating the expression (1.png) in both QE and EPW, \omega_{q,\nu} from previous (normal) DFPT calculations is used; it corresponds to the phonon frequency we normally obtain from phonon (ph.x) c...
by hlee
Fri Oct 01, 2021 7:12 pm
Forum: Running the code
Topic: Error in anisotropic calculation
Replies: 11
Views: 264

Re: Error in anisotropic calculation

Dear Mehmet: Please look at this line (https://gitlab.com/QEF/q-e/-/blob/develop/EPW/src/supercond.f90#L520). In your case, ibin has a negative value of -332. Usually, dosef, wf, and g2 have non-negative values and the issue above doesn't happen (I assume that you don't set shortrange to .true. and ...
by hlee
Wed Sep 29, 2021 7:33 pm
Forum: Running the code
Topic: Error in anisotropic calculation
Replies: 11
Views: 264

Re: Error in anisotropic calculation

Dear Mehmet: At line 522 of file supercond.f90 Fortran runtime error: Index '-332' of dimension 1 of array 'lambda_pairs' below lower bound of 1 The error message above tells us that there is a out-of-bound error; the first dimension of the array 'lambda_pairs' is smaller than one; this should not h...
by hlee
Wed Sep 29, 2021 7:15 pm
Forum: General discussion
Topic: What is the bare phonon frequency in EPW
Replies: 6
Views: 201

Re: What is the bare phonon frequency in EPW

Dear Zishen: Although there is no direct output of the bare phonon frequency in QE and EPW, we can obtain the bare phonon frequency by using the following formula under the double delta approximation: In EPW, it comes from the previous DFPT calculations on coarse grids and then interpolated on fine ...