[Wien] quasiparticles

[koitzsch]

Hi everybody,

I was wondering if somebody could point out some references for me about the
following problem:

If you read introductions about DFT from like S. Cottenier (on the Wien2k
user site) you always find statements like "the single particle
wavefunctions phi are not the wave functions of electrons but of
quasiparticles without a direct physical meaning. The single particle
energies e_i are not single-electron energies". Nevertheless people very
sucessfully compared directly band structure measurements (which have a
direct physical meaning) and the output from lets say Wien2k. The Au(111)
surface state, which Prof. Blaha has calculated is a nice expample of that.
The comparison worked not only for the Fermi energy but for higher binding
energies as well.

Could somebody explain or point out further reading, why such a comparison
is obviously valid?

Thank you very much

Best Regards

Christian Koitzsch
Uni Neuchatel
Dep. of Physics
CH-2000 Neuchatel
Switzerland