Lisa,
On Mon, Feb 3, 2014 at 12:27 PM, Lisa Bovenkamp
Hello.
I am running some EXAFS simulations Au L3 on Au clusters with SR coating. In the outer shell Au sits between 2 S atoms. 4 Au atoms are in the neighborhood up to 3.5 Angström. Expecting two peaks in the chi(R) - one for Au-S and one for Au-Au (here it can be several little ones) I find that for 1 out of 5 sites the Au-Au peak is way too high. Is something in the FEFF code weighing an Au-Au path for this site too much? Does anyone have some ideas on that?
Thanks, Lisa
I'm a little confused by what you're asking. Is SR "scratch resistant"? As Scott points out, you should not expect one peak for Au-S and one peak for Au-Au in chi(R). Au-Au will almost certainly give a double peak in chi(R) due to the resonance in the scattering for heavy scatterers. When you say "for 1 out of 5 sites the Au-Au peak is way too high", what are you comparing it too? Are the path degeneracies the same, is there any disorder term included in the simulation, etc. But if you're running a simulation, wouldn't you know what scattering paths contributed to the different peaks, and especially if the paths include multiple scattering? --Matt