About yambo_ph executable

[claudio]

Dear claudio，

First of all, I would like to express my appreciation for your work in developing Yambo software—it has been incredibly helpful for my research/project. I am writing to inquire about the yambo_ph executable. We are testing the electron phonon coupling module according to the tutorial, using the command line:

yambo_ph -g n -p fan -c ep -V gen

I can completely reproduce the results in the web page. This calculated bandgap only has the accuracy of standard DFT.


Question:

However, I want to perform the calculation including both the electron-phonon coupling and the electron-electron coupling with GW level. So I added a new option “ee”, the corresponding command line is:

yambo_ph -g n -p fan -c ee -c ep -V gen

I find the program will not work using the command above. The program will stop at once without calculated output. I also tested other functional such as PPA, the calculation still fails to give any useful output.


Thank you very much for your time and assistance. I look forward to your response.

Best regards,
Yang
(moved from my email to Yambo-forum, Claudio)

[claudio]

Dear Yang

I notice now that you already posted this question on the forum here:
viewtopic.php?t=2845

> However, I want to perform the calculation including both the electron-phonon coupling and the electron-electron coupling with GW level. So I added a new option “ee”, the corresponding command line is:
>
>yambo_ph -g n -p fan -c ee -c ep -V gen
>
>I find the program will not work using the command above. The program will stop at once without calculated output. I also tested other functional such as PPA, the calculation still fails to give any useful output.

not sure why this happens, we have to check.
In the while I advise you to perform two different calculation one for EE and nother for EP and put the results
in two different folders, using -J
yambo -F yambo_ph.in -J EP

and

yambo -F yambo_ee.in -J EE

than you can joint the two quasi-particle databases using the command ypp -qpdb m
https://wiki.yambo-code.eu/wiki/index.p ... sing_(ypp)

see also the discussion here:
https://yambo-code.eu/forum/viewtopic.php?t=2118

let us know if it works
best regards
Claudio Attaccalite

[bowen yang]

Dear claudio,
I am grateful for your timely response. I will certainly give your suggestions a thorough try and make sure to provide feedback on the results promptly. Once again, thank you for your invaluable guidance!
Best regards,
Yang

[bowen yang]

Dear Yang

I notice now that you already posted this question on the forum here:
viewtopic.php?t=2845

> However, I want to perform the calculation including both the electron-phonon coupling and the electron-electron coupling with GW level. So I added a new option “ee”, the corresponding command line is:
>
>yambo_ph -g n -p fan -c ee -c ep -V gen
>
>I find the program will not work using the command above. The program will stop at once without calculated output. I also tested other functional such as PPA, the calculation still fails to give any useful output.

not sure why this happens, we have to check.
In the while I advise you to perform two different calculation one for EE and nother for EP and put the results
in two different folders, using -J
yambo -F yambo_ph.in -J EP

and

yambo -F yambo_ee.in -J EE

than you can joint the two quasi-particle databases using the command ypp -qpdb m
https://wiki.yambo-code.eu/wiki/index.p ... sing_(ypp)

see also the discussion here:
https://yambo-code.eu/forum/viewtopic.php?t=2118

let us know if it works
best regards
Claudio Attaccalite

Dear Claudio

Thank you so much for your suggestion. My question has been successfully resolved. I truly appreciate your advice, as performing the two calculations separately and then merging the data proved to be a very effective approach. I’m deeply grateful for your help!

Best regards
Yang

[Harshita]

Dear Claudio,

I am having some difficulty in QP band correction step in Electron-phonon coupling.

At the step transferred momenta step, it shows the following error:

<---> [03] Transferred momenta grid and indexing

[ERROR] STOP signal received while in[03] Transferred momenta grid and indexing
[ERROR] Reading File ; Variable PH_FREQS1; NetCDF: Not a valid ID

Can you tell me what could be the possible problem? Please find the input file attached herewith.

Thanks and regards,
Harshita

[claudio]

Try to repeat calculation from the beginning,
there is a problem with some databases.
Did you manage to reproduce the tutorial?

best
Claudio

[Harshita]

Dear Claudio,

Thank you for the response.

Yes, I have reproduced the results of the tutorial. Additionally, I have successfully used it for another material as well, but this error is new.

Try to repeat calculation from the beginning,

By this, you mean from the phonon step or the dvscf step?

Best regards,
Harshita

[Harshita]

In continuation to the above,

If I now use ypp_ph to import electron-phonon coupling, it shows:

<---> [06] == Electron-Phonon Databases ==
<---> Inspecting databases ...not found

This is completely surprising as this step was successfully completed. Please find the log file attached here.

Best Regards,
Harshita

[Harshita]

Dear Claudio,

This problem is solved.

If I now use ypp_ph to import electron-phonon coupling, it shows:

<---> [06] == Electron-Phonon Databases ==
<---> Inspecting databases ...not found

Import in Yambo is successful, yet again the same error persists.

<---> [03] Transferred momenta grid and indexing
[ERROR] STOP signal received while in[03] Transferred momenta grid and indexing
[ERROR] Reading File ; Variable PH_FREQS1; NetCDF: Not a valid ID


I have also rechecked that all the previous steps are completed successfully.
If you could please help me with this, I would be highly grateful.

Best Regards,
Harshita