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VASP cannot calculate forces on atoms in the presence of electric field.

Posted: Sat Apr 12, 2025 6:36 am
by hszhao.cn@gmail.com

Hi there,

Recently, I learned that VASP cannot calculate forces on atoms in the presence of electric field. However, I do not have experience in this area, so I would like to obtain confirmation from the developers. Is that really the case?

Regards,
Zhao


Re: VASP cannot calculate forces on atoms in the presence of electric field.

Posted: Mon Apr 14, 2025 10:27 am
by michael_wolloch

Dear Zhao,

No, VASP can calculate forces in the presence of an electric field.

The procedure is a bit different depending on the system symmetry:

  • For a slab (or nanowire or molecule) you should set EFIELD, IDIPOL and LDIPOL.

  • For a bulk system, EFIELD_PEAD and PEAD_RELAX = .TRUE. need to be set.

Please search the Forum for similar posts before creating a new topic according to our posting guidelines. Similar issues have been discussed quite recently e.g.:
Running AIMD with electric field
and especially:
Electric field contribution to forces with EFIELD_PEAD

If you are specifically interested in phonons, please provide a minimal reproducible example of your calculation so that I can assist with that problem.

Cheers, Michael


Re: VASP cannot calculate forces on atoms in the presence of electric field.

Posted: Mon Apr 14, 2025 1:45 pm
by hszhao.cn@gmail.com
michael_wolloch wrote: Mon Apr 14, 2025 10:27 am

Dear Zhao,

No, VASP can calculate forces in the presence of an electric field.

The procedure is a bit different depending on the system symmetry:

  • For a slab (or nanowire or molecule) you should set EFIELD, IDIPOL and LDIPOL.

  • For a bulk system, EFIELD_PEAD and PEAD_RELAX = .TRUE. need to be set.

Please search the Forum for similar posts before creating a new topic according to our posting guidelines. Similar issues have been discussed quite recently e.g.:
Running AIMD with electric field
and especially:
Electric field contribution to forces with EFIELD_PEAD

Thank you very much for your suggestions and links to the discussions that have been conducted.

michael_wolloch wrote: Mon Apr 14, 2025 10:27 am

If you are specifically interested in phonons, please provide a minimal reproducible example of your calculation so that I can assist with that problem.

Cheers, Michael

In fact, I'm running the example here with the help of phonopy, and still haven't tried the pure VASP's way with the presence of an electric field. I don't know if there are similar examples of existing calculations based on VASP only.

Regards,
Zhao


Re: VASP cannot calculate forces on atoms in the presence of electric field.

Posted: Mon Apr 14, 2025 2:01 pm
by michael_wolloch

Dear Zhao,

I am glad to be of help. Please update the topic if you run into any issues with the example you are trying.

Cheers, Michael