[Wien] XSPEC valence lifetime Bbroadening

[Andrei Postnikov]

Dear WIEN2k developers,

I have a remark concerning the broadening of emission spectra
calcuated by the XSPEC script, and, specifically, its post-processing
by LORENTZ. It seems (please correct me if I am wrong!) that there might be
a problem if we deal with a split emission spectrum, like L_II,III,
AND introduce a non-zero broadening W (for the lifetime of valence states).
The spectra prior to broadening are provided by TXSPEC, which
weights two contributions, displaces them by SPLIT and puts
into the common energy scale, in which zero (= Ef) is at the top
of, say, L_III band, and L_II is displaced upwards:

     ***
   ******      ***
  ********   ******
---------O----------

This raw spectrum is written (by TXSPEC) to the 2d column of .txspec*
and then read in by LORENTZ. The valence state lifetime broadening is
organized such that it increases downwards from the Fermi energy.
However, as the broading parameter has quadratic dependence on (E-Ef),
being zero at Ef and W at E0 < Ef,
the broadening also increases upwards into positive energies
and smears out the L_II band just too much
(because of its energy separation from the L_III); moreover,
the broadening is inverted (the states at its top are the most broadened).
I think, the valence-sate lifetime broadening must be identical
throughout both L_III and L_II bands, increasing downwards from the top.
However, this is difficult to organize if the broadening (in LORENTZ)
is completely decoupled from splitting (in TXSPEC).
A solution could be to proceed with just one spectrum (L_III) through all
broadening routines and then overlap it with its shifted and scaled replica.
In doing so, one could simultaneously provide a summation over spins,
which is often needed.

Best regards,

Andrei Postnikov

 +-- Dr. habil. Andrei Postnikov ----- Tel. +49-541-969.2377 -- Fax .2351 ---+
 | Universitaet Osnabrueck - Fachbereich Physik, D-49069 Osnabrueck, Germany |
 +-- apostnik at uos.de --------- http://www.home.uni-osnabrueck.de/apostnik/ --+