[Wien] about oscilations of scf procedure

[Hua Wu]

I would suppose the oscilation occurs for a metallic solution. 
It seems due to the partial occupation of the narrow 
Re 4f bands. Firstly, you can try to use a small mixing
parameter like 0.01-0.05 or to increase the k-points.
Another option is to lower the crystal-field symmetry
(e.g, set cubic to orthogonal, but keep the atomic
positions), or to include the spin-orbit coupling which 
is normally important for Re,
finally to lift the orbital degeneracy. As a result,
the Hubbard U may help you to find a stable solution
with some orbitals (others) fully occupied (unoccuoied).

On Thursday 18 August 2005 05:02, zhoukj wrote:
> Dear all
>    I'm now using LDA+U do the calculation of rare earth
> oxides. When I put 4f orbital as the correlated orbital,  and
> run scf, I found that the scf procedure oscilates, but it is
> convergent. What's the problem?  Should I add spin-orbit in
> the calculation? How to set it? Thanks a lot.
>
>
>
>
> Sincerely yours,
> Zhou Ke jin
>
>
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>                       Beijing Synchrotron Radiation Facility
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> mail:Kejin.Zhou at ihep.ac.cn
>
>                       10:31:57    2005-08-18
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-- 
Dr. Hua WU

II. Physikalisches Institut
der Uni. zu Koeln,
Zuelpicher Str. 77,
D-50937 Koeln
Germany

Email: wu at ph2.uni-koeln.de
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