I want to test different exchange correlational functional on Magnesium silicide to investigate the electronic properties. For example, if I have the POTCAR library for various pseudopotentials of Mg and Si where we can specify the type of functional from the title/header let's say PBE. How can I change this PBE to PW91 in INCAR to see the effect? The following screencast is my INCAR for structure relaxation.

enter image description here


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    $\begingroup$ In the future, please don't add additional questions as new answers. If it is a minor addition, you can edit it into the original question. For larger changes, generally you should create a brand new question. $\endgroup$
    – Tyberius
    Mar 15 '21 at 17:08
  • $\begingroup$ @Shalini can you please copy and paste the INCAR into a code block rather than posting a screenshot? This way it's searchable and does not take so long to load on people's computers! $\endgroup$ Mar 15 '21 at 22:50

How can I change this PBE to PW91 in INCAR to see the effect?

  • According to the element order of your POSCAR, concatenate the different POTCARs in the GGA pseudopotentials library to generate the final POTCAR.

  • Set the GGA tag in INCAR (All other tags in your screencast is OK to me.):

    • PBE (default):

    • PW91

    • PBEsol:


More settings can refer to this link: https://www.vasp.at/wiki/index.php/GGA

Hope it helps.

  • $\begingroup$ Thanks for reply . Could you please check attached INCAR and give feedback which I understood that just change the value in GGA tag according to different functionals . $\endgroup$
    – Shalini
    Mar 15 '21 at 13:27
  • $\begingroup$ @Shalini It's OK to me. $\endgroup$
    – Jack
    Mar 15 '21 at 14:17
  • $\begingroup$ @Jack should the follow-up be a separate question? Anyway here is the link to the user's screenshot: i.stack.imgur.com/jkHhn.png, the answer will be deleted. $\endgroup$ Mar 15 '21 at 15:20
  • $\begingroup$ @NikeDattani It's not necessary. His question is not well organized. $\endgroup$
    – Jack
    Mar 15 '21 at 22:35
  • $\begingroup$ @NikeDattani I have re-organized the question post. $\endgroup$
    – Jack
    Mar 15 '21 at 22:47

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