[Wien] unoccupied DOS continuum states

[Peter Blaha]

> we calculate the unoccupied DOS at high energies (up to 70 eV above the Fermi level)because we are interested in the excitation spectra. Our results are systematically too low at high energies compared to experiments and to calculations with a hydrogenic model.
> Possible reasons for the discrepancy are :
> * DFT is not suited for excited states.

This is for sure one of the reasons. IT's a "fundamental" reason and only
more evolved methods like GW or TD-DFT might help.

> * the (L)APW+lo basis set is only good in a limited energy region.

This could be a "technical" problem with our linearized methods. Try to
add local orbitals at high energies (eg. 3Ry) and check if the spectrum
is sensitive to it.


                                      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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