[Ifeffit] XANES / NEXAFS with feff8.4

[s440697 at stud.uni-goettingen.de]

Hallo @all,

(first at all, sorry for my bad english)

i'm a student working on my diploma thesis (nexafs/xanes) and my job is to
simulate with FEFF 8.4 spectra, for example absorption as a function of
energy (mu_(E)). I'm a newbie in this topic and i tried to get the k-edge
of Sulfur for the substance gypsum (CaSO4 * 2(H2O)) and pyrite (FeS2). I'm
interested in the XANES-range of the spectra not the EXAFS. I get
everytime my peaks at ~2472 eV for Sulfur as absorber whatever substance i
use (gypsum, pyrite,...). There are no differences with the peak position
on the energy-scale or shifts. I'm really confused :-( I think, there
should be differences in the spectra... I send you two feff.inp files from
my feff-runs. My source is the mineralogy database
(http://rruff.geo.arizona.edu/AMS/amcsd.php) where i get the data for the
unitcell. Then i put the data in the XtalDraw program to get the positions
of the Atoms in Angstrom, by the way i get i nice 3D-View of the unitcell
:-). Then i put the values of the positions into feff...
I simulated pyrite with 12 atoms and gypsum with 48.
I'm appreciative for every help :-)

ciao,
Eckhard


---------------------------------
Eckhard Bosman
e.bosman at stud.uni-goettingen.de
+49 (0)551-39-14441
Raum: E0.104
Institut für Röntgenphysik
Friedrich-Hund-Platz 1
37077 Göttingen
Germany


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