EPW Forum

Dear Shashi, As you suggested I checked the matrix elements away from the Gamma point, and found that they are not Hermitian even there. Also, the system (monolayer h-BN) is TRS preserved, and the modes in prefix.dyn1 are completely real. However the matrix elements are not Hermitian. Here is my ...

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 ...

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

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

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 ...

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 ...

Dear Xiaozha,

It is helpful, yes.
Thank you,

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

Okay I found the issue. It was fsthick which was creating the problem.

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