Dear Nic, I've had a short look into your Artemis file. First of all, it seems that something's wrong with the Gd2O3 structure data in your feff.inp. Running feff on your feff.inp gives this error: Feff 8.40 ... WARNING: TWO ATOMS VERY CLOSE TOGETHER. CHECK INPUT. atoms 8 14 8 2.24848E+00 2.70250E+00 0.00000E+00 14 2.47549E+00 2.70250E+00 0.00000E+00 Run continues in case you really meant it. WARNING: TWO ATOMS VERY CLOSE TOGETHER. CHECK INPUT. atoms 9 15 9 -2.24848E+00 -2.70250E+00 0.00000E+00 15 -2.47549E+00 -2.70250E+00 0.00000E+00 Run continues in case you really meant it. [...] It seems that all your "Gd2" atoms have a duplicate in your "Gd3" atoms, shifted only by ~0.2 angstroms in either x,y, or z direction. Looking further at your feff.inp, already your ATOMS input somehow looks broken: (your ATOMS list) * Gd 0.25000 0.25000 0.25000 Gd1 1.00000 * Gd 0.02100 0.00000 0.25000 Gd2 1.00000 * Gd 0.54200 0.00000 0.25000 Gd3 1.00000 * O 0.12500 0.12500 0.37500 O1 1.00000 * O 0.12500 0.37500 0.37500 O2 (my list, cif file from ICSD, Shuenn et al., J. Chin. Chem. Soc. 57 (2010), 938) Gd 0.25 0.25 0.25 Gd1 1.000 * (8b position) O 0.3904 0.1513 0.379 O1 1.000 * (48e position) Gd 0.9710 0 0.25 Gd2 1.000 * (24d position) Using this crystal data, I was able to fit your data reasonably well (didn't tweak to make the fit perfect though...) - see attached file! I've also attached the .cif file that I've used, in case you want to compare with yours. BTW, enot values of >20 eV shouldn't really happen in any fit. Best regards, Dominik On 02.08.2011 04:42, Nicholas.Tse@csiro.au wrote:
Thank you all the suggestions.
I believe the ATOM model used is representative of what it should be. I generated the FEFF file from the CIF file from the American Mineralogist X'stal DB. The generated FEFF has the edge L3 that should be fine. A simple summation of the scatter paths does roughly produce the pattern for the sample, except for the amplitudes.
The enot was found to be 53.8995 +/- 2.7632.
I have also included the .prj and .apj files for your inspection.
Regards,
Nic
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-- Dr. Dominik Samuelis d.samuelis@fkf.mpg.de Max-Planck-Institut für Festkörperforschung Max Planck Institute for Solid State Research Heisenbergstr. 1 70569 Stuttgart Germany Phone +49-711-689-1769 Fax +49-711-689-1722 Web http://www.fkf.mpg.de/maier/