questions about the parameters

[jin.zhang]

Dear EPW users,

I am learning how to use EPW code to perform some researches. At first, I have run and analyzed the examples provided in the EPW package (in QE.6.0) carefully and there are some questions about the parameters. Thus, I need your help.

*Before running epw.x, I am confused how to set K_PONITS in the nscf_epw.in file. I met several errors such as "kmesh_get_automatic" and "Non-symmertric k-points neighbors' from wannerize routine. Could you introduce briefly how to generate these parameters? Maybe kmesh.pl can work, I am not sure.

*Can anyone explain the usage of the K path after "/" at the end of the epw.in file? I didn't find any description about this section.

*I hope anyone can give me an extra example for the transport properties of semiconductors/metals, and more descriptions will be much appreciated.

Thank you for your help in advance.

[sponce]

Dear Jin,

Thank you for your interest in the EPW code. I'll try to answer your questions:

1) You need to manually set the k-point in the nscf_epw.in file. All the points have to be between 0 and 1 and be homogeneous. So a 6x6x6 corse k-grid will have 216 points between 0 and 1. You can use bash, python, matlab etc to generate that grid.

2) No use at the moment

3) The only example is about electronic transport in metal (pb) via the Eliashberg transport function. I'm currently developing an implementation for electronic
transport in semiconductor but it's not finished yet.

Best,

Samuel

[jin.zhang]

Dear Samuel,
Thank you for your prompt reply.
Hope you finish the work about the transport properties earlier.
Jin