[Wien] Energy convergence with spin-orbit

[Laurence Marks]

I have only done a few -so calculations, but from the list they seem to
lead to problems. A few suggestions:

a) Check for user error when you setup the in plane calculation. Have you
used the right symmetry reduction? This seems to be the most common issue.

b) Check that you are using the patches for issues in initso that have been
posted.

c) Look if your calculation is oscillating or just veeeeeery slowly
converging. You can do a grep on some of the moments such as :ORB, :POM,
:SPI in case.scf. I have seen these only slowly converge as the occupied
states change.

d) Think carefully about the physics of your problem. Some time ago I did a
test LDA+U calculation for a Ni (metal) surface. It did not converge, which
was OK. In Wien2k you are solving a fixed-point problem, and always
assuming that such a solution exists. I do not believe that anything
guaruntees that a solution exists in all cases. ( This is different from
doing a variational calculation.) Maybe with your distances your impurities
want to have an AFM ordering in-plane, but you are preventing this.

These are just guesses, without more information it is hard to know.

---
Professor Laurence Marks
Department of Materials Science and Engineering
Northwestern University
http://www.numis.northwestern.edu
Corrosion in 4D http://MURI4D.numis.northwestern.edu
Co-Editor, Acta Cryst A
"Research is to see what everybody else has seen, and to think what nobody
else has thought"
Albert Szent-Gyorgi
On Feb 12, 2016 06:19, "Islam, Md F" <islamm at uta.edu> wrote:

> Dear Wien2k users,
>
>     I am trying to do a magnetic impurity calculation on a surface
> including spin-orbit coupling.
> I set the energy and charge convergence to 0.00001 and 0.001,
> respectively. The calculation is
> well converged if magnetization is in-plane but for out of plane
> magnetization it is not converging.
> While charge satisfies convergence criterion very well, the energy keeps
> oscillating near the 3rd/4th
> decimal places.. I tried with different mixing (MSR1: 0.05 to 0.01) but
> nothing seems to be working
> for about 2 months. For larger mixing, job crashes with QTL-B error. I
> would appreciate if you can
> give me some suggestion to resolve the problem.
>
>    I am also wondering if anyone has done any anisotropy calculation with
> both self-consistent and
> non self-consistent methods and whether they give the same anisotropy
> energy.
>
>
> Thanks,
> Fhokrul
>
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