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Electron-Phonon Matrix Elements EPW

Posted: Thu Sep 21, 2023 4:56 pm
by animeshd
Hi, I am trying to calculate the shortrange electron-phonon matrix elements using EPW. Once the run is completed the ephmat files are generated. I understand that the files are in binary format. Is there any way to convert the files into text format so that I can open them to see the contents of the file?

It would be great if someone could provide some information on this.

Thanks

Re: Electron-Phonon Matrix Elements EPW

Posted: Sat Sep 23, 2023 9:31 pm
by stiwari
Hi,

The ephmat file is written in binary because if it is written as a text file then it's size will be quite large.
A good idea would be to read the ephmat files directly as binary instead of trying to convert it into a text file.

You can use subroutine "read_ephmat()" in EPW/src/io_eliashberg.f90 for inspiration on reading the binary file.

Best,
Sabya.

Re: Electron-Phonon Matrix Elements EPW

Posted: Mon Sep 25, 2023 7:39 pm
by animeshd
Hi,

Thank you for the clarification. But is there a way to change the output format? I will calculate on a coarse grid to check the format of the file and then while using a dense grid, I will use the binary format of the file so that memory is not a problem.

Thanks
Animesh

Re: Electron-Phonon Matrix Elements EPW

Posted: Mon Oct 02, 2023 6:13 pm
by hmori
Hi Animesh,

We do not provide an option to change the file format, so you have to modify "write_ephmat()" in EPW/src/io_eliashberg.f90 to change the format yourself.

Best,
Hitoshi

Re: Electron-Phonon Matrix Elements EPW

Posted: Wed Oct 25, 2023 3:57 am
by johnnywow
Hi,

Should I change the "FORM = 'unformatted'" to "FORM = 'formatted'" in OPEN()?
I notice that there are !OPEN(FORM = 'formatted') before or after the OPEN(FORM = 'unformatted').
Since I have no experience in Fortran, Could you give me some advices?

Best,
John

Re: Electron-Phonon Matrix Elements EPW

Posted: Mon Oct 30, 2023 11:13 pm
by hmori
Hi John,

Yes, you can change the format to human-readable one by changing "FORM = 'unformatted'" to "FORM = 'formatted'".
Note that the file size may become larger than that of the binary format.

Best,
Hitoshi