[Wien] missing electrons

Peter Blaha pblaha at zeus.theochem.tuwien.ac.at
Tue Sep 14 12:15:48 CEST 2004


> I had experienced the problem of "missing electrons" and therefore, I
> have generated the density of states (DOS) by broadening the eigenvalues
> (available from the case.output1 file) by a gaussian. (i.e.  I have
> scrupulously worked on the algorithm that you had suggested sometime
> back  to generate the DOS.)  Now, I miss only 2 electrons in the 4-sigma
> state of CO (i.e. the integration of DOS over the 4-sigma peak yields 2
> instead of 4.) 4 electrons are expected  in this state due to the
> presence of 2 CO molecules in the structure file.
>
> The case.outputt file confirms the presence of 4 electrons in the
> 4-sigma state in its column for the integrated DOS. So, it becomes
> apparent that WIEN prints the eigenvalues in the case.output1 file only
> once even if they actually occur more than once. It could  be possible
> that WIEN stores such a degeneracy internally.

No, WIEN prints all eigenvalues, and if they are degenerate, it will print
them 2 or 3 times.

However, in a non-spinpolarized calculation you should include the
spin-multiplicity of 2 ! (2 electrons occupy a single eigenvalue).

PS: Should you ever publish such broadened DOS, be carefull !
CO states may need a smaller broadening  (if they are isolated, they
might have no k-dispersion), than metal states !


                                      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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