EPW Forum

Dear developers,

I am working on calculating the electroacoustic scattering rate in thermal conductivity.
Running memory problems were encountered due to the high number of atoms. When I get the epb file and try to get the ephmat file, the calculation breaks due to out of memory. I next want to replace the larger memory computing. I would like to know how to skip the time consuming epb calculation and do the ephmat acquisition directly? What parameters do I need to set. Here are my current main parameter settings:
etf_mem = 0
elph = .true.
kmaps = .false.
epbwrite = .true.
epbread = .false.
epwwrite = .true.
epwread = .false.
elecselfen = .true.
phonselfen = .false.
parallel_k = .true.
parallel_q = .false.

Thank you very much!

Best regards,

Shengnan Dai

Dear Shengnan Dai:

First of all, it seems that you are using the old version of EPW; so I would like to suggest you the recent one which can be downloaded at https://docs.epw-code.org/doc/DownloadAndInstall.html .

Regarding your question:
You can skip the evaluation of epb by using the input flag of " epbread=.true. " (https://docs.epw-code.org/doc/Inputs.html#epbwrite), however, it is necessary to use the same number of cores to restart the runs from the epb files since there files are written per process.

Lastly, I would like to suggest you to check the materials covered in EPW school 2022 at https://epw2022.oden.utexas.edu/ .

Sincerely,

H. Lee