Search found 67 matches

by simba2828
Fri Apr 10, 2026 5:17 pm
Forum: Electron-phonon
Topic: electron-phonon matrix elements are not hermitian
Replies: 2
Views: 25005

Re: electron-phonon matrix elements are not hermitian

Dear Shashi, Thank you for your reply. Yes the system is TRS preserved. I haven't checked the q\=0 case but will definitely check. Meanwhile I am trying to print the el-ph matrix elements from PHonon routine of ph.x. Is there any way I can print the matrix elements for given k points. I am using the ...
by simba2828
Mon Feb 23, 2026 4:27 pm
Forum: Electron-phonon
Topic: electron-phonon matrix elements are not hermitian
Replies: 2
Views: 25005

electron-phonon matrix elements are not hermitian

Dear experts,

From my EPW calculation, the electron-phonon matrix elements at q = 0 are not Hermitian, i.e,

g_{n,m}^\nu ≠ g_{m,n}^\nu*

Could anyone please tell the possible reason?

I am using EPW6.0 where I can print the complex electron-phonon matrix elements.

Sincerely,
Shubham
by simba2828
Tue Dec 23, 2025 3:08 pm
Forum: Running the code
Topic: el-ph matrix elements in complex form
Replies: 2
Views: 30959

Re: el-ph matrix elements in complex form

Dear all,

I just found out that this routine printing.f90 has been updated in the latest version. And I can get the complex number from there.

Thank you very much.

Sincerely,
Shubham
by simba2828
Tue Dec 23, 2025 1:36 pm
Forum: Running the code
Topic: el-ph matrix elements in complex form
Replies: 2
Views: 30959

el-ph matrix elements in complex form

Dear Experts, I want to use el-ph matrix elements generated from EPW, which are stored in absolute numbers (|g|) and not in general complex form. Is there any way I can find the actual complex numbers for g^ij_v? The data I get currently from EPW is the following. (The last column is a modulus of g ...
by simba2828
Fri Nov 14, 2025 10:38 am
Forum: Theory
Topic: SCF potential in Born effective Charge
Replies: 1
Views: 44002

SCF potential in Born effective Charge

Dear developers and Experts, Is it possible to collect/extract the dV_scf/du term as shown in the picture attached using QE/EPW? This is a formula for calculating the Born effective charge. I am sure this data (dV_scf) is stored somewhere (most probably in the binary files *.dvscf). If someone knows ...
by simba2828
Fri Aug 08, 2025 1:27 pm
Forum: Running the code
Topic: el-ph matrix elements along some kpath?
Replies: 2
Views: 43293

Re: el-ph matrix elements along some kpath?

Dear Xiaozha,

It is helpful, yes.
Thank you,
by simba2828
Thu Aug 07, 2025 4:56 pm
Forum: Running the code
Topic: el-ph matrix elements along some kpath?
Replies: 2
Views: 43293

el-ph matrix elements along some kpath?

Dear experts,

Is it possible to calculate the electron-phonon matrix elements (g) along some kpath and not on a grid?
Can I give any random k point and EPW calculates the g for the chosen q and k?

Thanks,
Shubham
by simba2828
Thu Aug 07, 2025 4:43 pm
Forum: Running the code
Topic: zero electron-phonon matrix elements |g|
Replies: 2
Views: 41359

Re: zero electron-phonon matrix elements |g|

Okay I found the issue. It was fsthick which was creating the problem.
by simba2828
Thu Aug 07, 2025 3:30 pm
Forum: Running the code
Topic: zero electron-phonon matrix elements |g|
Replies: 2
Views: 41359

Re: zero electron-phonon matrix elements |g|

Could it be because of small negative frequency?
Furthermore, there are six bands in my wannier basis, why the el-ph elements are calculated for the 3rd band only?

Thanks,
Shubham
by simba2828
Thu Aug 07, 2025 3:24 pm
Forum: Running the code
Topic: zero electron-phonon matrix elements |g|
Replies: 2
Views: 41359

zero electron-phonon matrix elements |g|

Dear all, I am trying to calculate the electron-phonon matrix elements |g| using EPW and I am getting all the elements to be zero. Is there any specific reason the g's are zero. There should be any non zero value, however small it is? I am attaching my input file (second step), and in the epw.out ...