[Wien] Pt atom in a box

[M. Todorova]

Thank you
Mira

Peter Blaha wrote:
> 
> > I am trying to calculate a Platinum atom in a box. The problem is, that
> > no convergence can be reached even after 100 iterations. The charge
> > distance seems to oscilate between values of 0.04-0.01.
> 
> As discussed previously, one should use a F-centered cubic cell with a
> sufficiently large lattice parameter (test it).
> 
> I don't think it is a problem of GGA, not would I use empty spheres!!
> 
> I would use a much smaller value of RKMax at the beginning (to make sure
> not to get problems from this). You can increase it later...
> 
> Most likely it is simply a well known DFT problem (both in LDA and GGA)
> that the atomic configurations of late transition metals does not come out
> correctly. You have the 5d and 6s orbitals as valece states. Now it
> probably happens, that when 6s is occupied with 2 electrons, it's energy
> raises and get higher than the 5d. Thus the occupation will change and 6s
> is occupied only by ONE electron. However, this changes the potential such
> that the 6s orbital will lower it's energy BELOW the 5d and in the next
> step it will be fully occupied again.......
> 
> I suggest you try a smearing method (TEMP or GAUSS with eg. 0.005).
> Together with small mixing a solution (with non-integer 6s occupation)
> should be possible.
> 
> PS: I've no experience with Pt, but this is from analogy to Fe, as
> discussed already in "Janak's" book on the elements.
> 
>                                       P.Blaha
> --------------------------------------------------------------------------
> 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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Mira Todorova                           todorova at fhi-berlin.mpg.de
Fritz-Haber-Institut, Abt. Theorie      Phone:  +49 30 8413 4808
Faradayweg 4-6                          FAX:    +49 30 8413 4701
D-14195 Berlin (Germany)                www.fhi-berlin.mpg.de/th
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