[Wien] sum of eigenvalue

[Peter Blaha]

No, state-tracking is not implemented.

Summing up eigenvalues "by hand" is not that easy for a metal.

You need to consider the different weights for different k-points, and
you need to consider that near EF some eigenvalues will not necessarily have
occupation 0/1, but better "integration methods" like TETRA or TEMP(S)
( and not the primitive "root-sampling" which you attempt) will
lead to partial occupations of those states.

For sure, SO can change the occupation of some states and I don't see
anything "bad" by that.

Am 10.12.2010 08:25, schrieb Bin Shao:
> Dear all,
>
> According the force theorem method, we can calculate MAE by the following steps in wien2k:
>
>    1. nosoc-scf
>    2. x lapwso -up
>    3. x lapw2 -so -up/dn
>    4. add "SUM of EIGENVALUE" of spin-up and that of spin-dn
>    5. get the difference of the above value with different directions of magnetization
>
> But when I intend to find the MAE contribution from different k-points, I encountered some problems. I tried to sum the eigenvalues at some special k-point manually from the
> case.energysodn/up files and used the fermi energy to determine the occupied states. Next I sum the eigenvalue of this occupied states including spin-up and spin-down and then get
> the difference of this values with different directions. In some cases, the contribution to MAE at a k-points maybe very large and the reason is that there may be one less
> occupied band near the fermi level in one direction than another. I have check the references and found a method called state-tracking to avoid this.
>
> So here is my question, how does the wien2k code obtain the "SUM of EIGENVALUE" in lapw2 to avoid the problem mentioned above? Please give me some comments, thank you in advanced!
>
> Best regards,
>
> --
> Bin Shao, Ph.D. Candidate
> College of Information Technical Science, Nankai University
> 94 Weijin Rd. Nankai Dist. Tianjin 300071, China
> Email: binshao1118 at gmail.com <mailto:binshao1118 at gmail.com>
>
>
>
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-- 

                                       P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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