[Pw_forum] Valence state identification for BaTiO3

[Nicola Marzari]

On 3/29/11 10:39 PM, Liwei Geng wrote:
> Dear all,
>
> I use atom pseudopotential files to do the scf calculation, but I can't
> know their valence state. Could you tell me how to identify the valence
> state of each ion in BaTiO3 using QE? Say, how can I know that the Ba is
> Ba2+ or O is O2-?
>
> Thanks,
>
> Liwei
>


The oxidation state is a phenomenological concept, and not well defined.
The closest physical thing is the Born effective charge.

The number of valence electrons for any pseudopotential is given
by Z valence, in the header of that pseudopotential file.

			nicola


-- 
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Prof Nicola Marzari    Department of Materials    University of Oxford
Chair of Materials Modelling  Director, Materials Modelling Laboratory
nicola.marzari at materials.ox.ac.uk     http://mml.materials.ox.ac.uk/NM