[Wien] sum of eigenvalue

[Peter Blaha]

The "weight" files as well as the "help" files (option -help) contain the "integration weights"
for each k-point and eigenvalue.

Am 10.12.2010 09:30, schrieb Bin Shao:
> Dear Prof. Peter Blaha,
>
> Thank you for your quick reply!
>
> I recheck the description of input file of lapw2 in UG and note the "efmod". But how to sum up eigenvalues at one single k-point in wien2k, can you give me some suggestions?
>
> On Fri, Dec 10, 2010 at 4:08 PM, Peter Blaha <pblaha at theochem.tuwien.ac.at <mailto:pblaha at theochem.tuwien.ac.at>> wrote:
>
>     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> <mailto:binshao1118 at gmail.com <mailto:binshao1118 at gmail.com>>
>
>
>
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>     --
>
>                                           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 <mailto:blaha at theochem.tuwien.ac.at>    WWW: http://info.tuwien.ac.at/theochem/
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>
>
>
> --
> 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
--------------------------------------------------------------------------
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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