[Wien] surface with mBJ

[Peter Blaha]

In principle you are doing it ok.

Are you using the latest mbj routines with all updates discussed in the
mailing list ?

Still, I could imagine that in the surface region (low density) the mBJ potential
diverges somehow, but I don't know this.

Are the Fourier coefficients of Vxc (printed in case.output0) converging ?
(There is a list of (h k l) with (0 0 i) and i ranges from 0 to some maximum.
The corresponding fourier coefficient is large for i=0 and i=max, but in the "middle" they
should be significantly smaller.)

Alternatively, try a surface calculations with a "small vacuum" only and see if mBJ
can handle this.

Am 05.01.2012 10:06, schrieb archieve mail:
> Hi Blaha,
>
> There is a paragraph about surface with mBJ in the usersguide.
> "
> The TB-mBJ potential uses an average of Drho=rho over the unit cell. This does not make sense for
> surfaces or molecules. In such cases, run a similar bulk structure first, then cp case bulk.grr to
> case.grr and remove case.in0 grr. This runs mBJ with a fixed value of “c”.
> "
>
> What does 'a similar bulk structure' mean? Now I want to calculate slab along (111) direction of NaCl
> structure. At first I converge a mBJ calculation of original NaCl structure with just two atoms. Then
> I copy bulk.grr to slab.grr to do the mBJ calculation. However the calculation divergence even if
> mixer is PRATT with mix beta 0.001.
>
> May be there is some faults in my calculation. Can you help me?
>
> Thanks a lot.
>
> Best,
>
> Yonghong Zhao
>
>
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-- 

                                       P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-165300             FAX: +43-1-58801-165982
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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