[Pw_forum] Ti pseudopotential

[Axel Kohlmeyer]

On Mon, Feb 25, 2008 at 3:56 AM, Helen <helen at fh.huji.ac.il> wrote:
>
>
> Hello,


helen,

> I have a question about example 10, which does calculations on PbTiO_3. The
> number of valence electrons specified is 25,  nbnd=25, corresponding to a Ti
> cation (4s2 3d1) and the Ti pseudopotential , Ti.vdb.UPF also states that it
> is generated for the cation,
> Wavefunctions         nl  l   occ
>                             3S  0  2.00
>                             3P  1  6.00
>                             4S  0  2.00
>                             3D  2  1.00
> Giving 11 valence electrons corresponding to 4s2 3d1.
> THough in the same file it states
>    12.00000000000      Z valence
> Is the calculation really being carried out for  PbTiO_3 with a titanium

it is quite common for transition metals to create pseudopotentials
from a (slightly) oxidized reference configuration to have improved
transferability. the use of resulting pseudopotential is independent
of the reference configuration, i.e. zv is the core charge in the calculations.

cheers,
    axel.

> cation and the rest neutral atoms? IF so why? Or is there something I am
> misunderstanding about how the pseudopotential and run file are made?
> Thank you,
> Dr. Helen Eisenberg,
> Fritz Haber Center,
> Hebrew University
> _______________________________________________
>  Pw_forum mailing list
>  Pw_forum at pwscf.org
>  http://www.democritos.it/mailman/listinfo/pw_forum
>
>



-- 
=======================================================================
Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
  Center for Molecular Modeling   --   University of Pennsylvania
Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
=======================================================================
If you make something idiot-proof, the universe creates a better idiot.