[Ifeffit] Autobk parameters

[Stefano Ciurli]

Hi folks,

guess what, another question...

I would like to estimate the area of a small pre-edge peak in a 
Nickel spectrum. It is known that the area of this peak, compared to 
the XANES, is correlated to the degree of symmetry for the Ni(II) 
ion. I tried to use the peak fitting procedure implemented in Athena, 
but unsuccessfully. If I limit the fitting region to close to the 
pre-edge peak, and use either gaussian or lorentzian lineshape, the 
fitting is bad, really bad (shift of the fitted maximum, wrong 
linewidth). Maybe the peak is just too small. If I try to fit the 
entire XANES in addition to this small peak, I get very good fit for 
the XANES features, but negative intensities for the pre-edge peak. 
Any clues?

Stefano
-- 
____________________________________________

Stefano Ciurli
Professor of Chemistry
Department of Agro-Environmental Science and Technology
University of Bologna
Viale Giuseppe Fanin, 40
I-40127 Bologna
Italy
Phone:	+39-051-209-6204
Fax: 	+39-051-209-6203

"Fatti non foste a viver come bruti,
ma per seguir virtute e canoscenza"
Dante Alighieri - Inferno - Canto XXVI