How to model an ion or put a charge on an atom

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seba_varghese
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How to model an ion or put a charge on an atom

#1 Post by seba_varghese » Wed Oct 13, 2021 3:50 pm

Hai VASP users,

I would like to model and simulate Strontium (II) cation or Sr (2+) in VASP. Can anyone please advise how to add a charge to an atom in VASP, in my case a charge of +2 to Strontium atom. I have seen some posts discussing the inclusion of NELECT tag (sets the number of valence electrons considering the charge state of ion) in INCAR file. But I understand that this NELECT tag is for the whole system (in my case, Sr(II) ion adsorbed on graphene oxide), not specifically for Sr(II) ion. So I doubt if I use NELECT tag alone in the INCAR file correctly model Sr ion adsorption on graphene oxide. It would be of great help if anyone clarifies on this or guide how to specifically model ions using VASP.

Thanks in advance,
Seba

fabien_tran1
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Re: How to model an ion or put a charge on an atom

#2 Post by fabien_tran1 » Tue Dec 14, 2021 9:28 am

Hi,

In general the oxidation state of an atom is determined by its environment. Adding a charge on a particular atom makes sense only for an isolated atom. If Sr(2+) is the natural oxidation state in your particular system, then this is what you should obtain at the end of your calculation. You can check that by analyzing the density.

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