[Wien] charging effects - manipulation of the valence electrons and background charge

[Peter Blaha]

> I have found confusing previous discussions on charging effects in the 
> mailing list.
> Therefore, I would like to ask you a couple of the following questions.
> 
> 1. Does the charging effects (manipulation of the valence electrons not 
> core hole) hold in
> general valid for any system?

I'm not sure what you mean by this question. I tend to answer "yes".
Please remember, total energy corrections as suggested in literature are
not included (see previous mails).

> 2. Is it always necessary to preserve a cell charge neutral? Is it 
> therefore obligatory when
> one puts more/less valence charge (increase/decrease number of valence 
> electrons in case.in2)
> decrease/increase background charge (in case.inm)? I have found that 
> playing with the
> background charging leads to the :ENE WARNING in case.scf.

Yes. (The program runs also without that, but you do something uncontrolled.

> 3. Is it possible to consider non integer charge contribution?

Yes.
-- 

                                       P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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