Just a guess but you might need to explicitly include a term for coordination number. Maybe the path you are getting is for just one U-O backscatterer. Sorry I can't be more definitive (having never used Larch for this purpose myself) but that's the only thing I can come up with.
On May 21, 2022, at 12:35 PM, juejing.liu@gmail.com wrote:
Hi,
I am recently trying to use Larch to fit XAS spectra of uranium compounds (e.g., UO2, using an existing CIF file). I did not achieve a good fit and the amplitude of the model is way lower than the data. Then I tried to plot the uranium oxygen 1st path with all 8 atoms a sigma2=0.001 by using the plot model function. The resulting scattering peak is still far lower than it should be (images below). Did I do something strange with the program?
The Larch version I used was 0.9.59. I can send the cif file and the UO2 data I used if necessary.
Best,
Juejing
Juejing Liu Guo Group Materials Science and Engineering program Alexandra Navrotsky Institute for Experimental Thermodynamics
Washington State University Pullman, WA 99164-4630 Office: Fulmer Hall, Room 630 Phone: 208-206-7304
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