Search found 415 matches

by hlee
Mon Jul 18, 2022 4:23 pm
Forum: General discussion
Topic: Couldn't reproduce phonon bandstructure with EPW but electron bandstructure is accurate.
Replies: 10
Views: 5222

Re: Couldn't reproduce phonon bandstructure with EPW but electron bandstructure is accurate.

Dear Prachi: Even if you used the default value for the acoustic sum rule, you can calculate the phonon dispersion with EPW starting from the interatomic force constants obtained by q2r.x ; please check the post above by Hari. This is the same as done in matdyn.x and I would like to suggest you to c...
by hlee
Wed Jul 13, 2022 9:23 pm
Forum: General discussion
Topic: Couldn't reproduce phonon bandstructure with EPW but electron bandstructure is accurate.
Replies: 10
Views: 5222

Re: Couldn't reproduce phonon bandstructure with EPW but electron bandstructure is accurate.

Dear Prachi:

Could you provide all inputs and outputs for the generation of phonon dispersions with ph.x (+q2r.x, matdyn.x, etc.) and EPW?

Sincerely,

H. Lee
by hlee
Tue Jul 05, 2022 4:16 pm
Forum: Running the code
Topic: error on running mgb2 example
Replies: 1
Views: 1631

Re: error on running mgb2 example

Dear Sumit Kukreti: Starting from EPW v5.4, the input keyword of kmaps is removed: https://docs.epw-code.org/doc/Releases.html#epw-v5-4 So you need to remove kmaps in your epw.in . PS) I confirmed this change was already made in the mgb2 example folder (EPW/examples/mgb2/epw) starting from QE v6.8 i...
by hlee
Tue Jun 28, 2022 6:44 pm
Forum: Running the code
Topic: Error in routine calbec (3): size mismatch
Replies: 3
Views: 2582

Re: Error in routine calbec (3): size mismatch

Dear jsli21: (from your epw.in) nbndsub = 4 ... proj(1) = 'Pb:sp3' (from your nscf.in) &system ... nat= 2 , ... / Since your system has two atoms per unit cell and you are using four projections per atom, nbndsub should be 8, NOT 4. Additionally, it is not directly related to your issue, but rigorou...
by hlee
Mon Jun 27, 2022 4:30 pm
Forum: Running the code
Topic: Error in routine calbec (3): size mismatch
Replies: 3
Views: 2582

Re: Error in routine calbec (3): size mismatch

Dear jsli21:

Could you provide nscf.in and full outputs of nscf.out and epw.out?

Sincerely,

H. Lee
by hlee
Mon Jun 27, 2022 4:27 pm
Forum: Running the code
Topic: help ! forrtl: severe (174): SIGSEGV, segmentation fault occurred
Replies: 2
Views: 2903

Re: help ! forrtl: severe (174): SIGSEGV, segmentation fault occurred

Dear Michael Kong:

(from your nscf.in)
...
ibrav = 12
lda_plus_u = .TRUE.
nat = 4
nspin = 2
ntyp = 3
...
EPW is not compatible with nspin=2. Also it doesn't work with LDA+U.

Sincerely,

H. Lee
by hlee
Wed Jun 22, 2022 3:01 pm
Forum: General discussion
Topic: 2D materials and EPW
Replies: 4
Views: 27807

Re: 2D materials and EPW

Dear jhosamelly:

The new version (EPW v5.5) also doesn't officially support the electron mobility of 2D materials.
We are still working on it.

Sincerely,

H. Lee
by hlee
Mon Jun 06, 2022 3:34 pm
Forum: Running the code
Topic: Error in routine read_ephmat
Replies: 1
Views: 1568

Re: Error in routine read_ephmat

Dear qdhao: You are encountering the issue with large memory footprint and you need to check my previous post at https://forum.epw-code.org/viewtopic.php?p=4497#p4497 . Well, this is not related to your issue, but I would suggest you to use norm-conserving pseudopotentials. Rigorously speaking, both...
by hlee
Sun Jun 05, 2022 4:23 pm
Forum: General discussion
Topic: Possibly inefficient call to ZAXPY and proposed performance enhancement
Replies: 2
Views: 2088

Re: Possibly inefficient call to ZAXPY and proposed performance enhancement

Dear Tianqi Deng:

Thank you very much for your fix.

Your fix clearly eliminates copy-in/copy-out here.

Even if in your fix, zaxpy deals with non-stride-1 access, usually dims is small and the size of temporary array for copy-in/copy-out is large; so your fix is more efficient.

Sincerely,

H. Lee
by hlee
Fri May 27, 2022 5:06 pm
Forum: General discussion
Topic: Error in routine read_frequencies
Replies: 9
Views: 6505

Re: Error in routine read_frequencies

Dear Ray: With the current version of the code, there are not many options. Basically, you need to change the value of input keyword max_memlt (https://docs.epw-code.org/doc/Inputs.html#max-memlt) so that this value is larger than your memory footprint. PS) Usually you need to reserve more memory pe...