EPW Forum

Dear EPW users and developers,

I am facing an issue while doing EPW calculation.
I use EPW and QE to calculate electron-phonon superconductivity of two isomerides.
One of them was working fine with QE and EPW.
For the other one, EPW calculations freeze without errors.
I found some strange messages in a phonon calculation using QE ph.x as follow.
I wonder if it is a bug in EPW. And what should I do for it?

QE ph.x messages
Dynamical matrices for ( 4, 4, 1) uniform grid of q-points
( 4 q-points):
N xq(1) xq(2) xq(3)
1 0.000000000 0.000000000 0.000000000
2 0.000000000 0.288675135 0.000000000
3 0.000000000 -0.577350269 0.000000000
4 0.250000000 0.433012702 0.000000000
Eigenvectors exchange needed 7 9
Eigenvectors exchange needed 9 10
Eigenvectors exchange needed 11 15
Eigenvectors exchange needed 13 17
Eigenvectors exchange needed 15 16
Eigenvectors exchange needed 17 18
Eigenvectors exchange needed 28 34
Eigenvectors exchange needed 30 36
Eigenvectors exchange needed 32 38
Eigenvectors exchange needed 34 35
Eigenvectors exchange needed 36 37
Eigenvectors exchange needed 38 39
Eigenvectors exchange needed 40 43
Eigenvectors exchange needed 42 45
Eigenvectors exchange needed 44 45

Yours sincerely,
pfliu

Hi pfliu89,

Is your .dvscf and .dyn files saved correctly? I did not see "Calculation of q = 0.00000000 0.00000000 0.0000000" in your log.ph file, are you aware of it?

Happy EPWing,
Hari

Hi Hari,

Thank you for your reply. I’m sure they are saved correctly. I calculate q=0 separately and it does not affect subsequent EPW calculations.
To guarantee it, I recalculate phonons use a traditional process but with the same problem in EPW.

Yours sincerely,
pfliu

Dear pfliu89:

Could you provide all inputs and outputs (nscf, ph, and epw calculations)?
In addition, could you confirm you encountered the same issue if you don't use 2D correction?

Sincerely,

H. Lee

Hi H. Lee,

Sorry for my late reply and thanks for your response.
I have tested it without 2D correction for the past few days and encountered the same issue.
Attachments are the inputs and outputs without 2D correction.

I am looking forward to your reply.

Yours sincerely,
pfliu

Hi H. Lee,

Sorry for my late reply and thanks for your response.
I have tested it without 2D correction for the past few days and encountered the same issue.
Attachments are the inputs and outputs without 2D correction.

I am looking forward to your reply.

Yours sincerely,
pfliu

hlee wrote: ↑Mon Oct 17, 2022 4:57 pm Dear pfliu89:

Could you provide all inputs and outputs (nscf, ph, and epw calculations)?
In addition, could you confirm you encountered the same issue if you don't use 2D correction?

Sincerely,

H. Lee