Juan: For S02 from fluorescence measurements or data collected at other times/beamlines, etc, I would ask what purpose this S02 is serving in your analysis. I'd guess that you do "the normal thing" of fixing this value for several paths and then float the coordination numbers so that amp = S02 * N for some number of paths. As you have experienced, S02 does have some inherent uncertainty in it due to modes of measurement and sample preparation. Be sure to fold that into your analysis!
I have more questions, related and not related to the last subject, but I am still thinking about them: The first one is easy, it is about the Nyquist theorem. I read in a paper that the formula is 2·deltak·deltaR/pi + 2. The last "+2" is new for me and I am afraid that Artemis does not consider it. I am sure that it is a silly thing.
Artemis/Ifeffit use (2 DeltaK DeltaR / pi) as a real number (not rounding) and leaves out the +2. I will describe this as "the correct way" of doing it. More importantly, if it matters for your results, the uncertainties in the fitted parameters *should* be very high.
I will try to correct again Ptfoil considering self-absorption in order to obtain a spectrum similar to Anatoly's or Bruce's one. And then, I will apply the same correction for supported platinum catalysts, right?
I'm not sure I understand this. But, you may want to apply absorption corrections to data collected in fluorescence when the Pt concentration is high (say, >1%), especially when comparing data with a range of concentration and where accurate absolute coordination numbers are important. Also, don't spend too much time analyziing the Pt foil just to get S02.
I also observed that Anatoly's Pt foil shows good signal even for large k (20 A-1). Nevertheless, obviously platinum catalysts spectra possess lower signal and specially for high values of k where the noise is big. The question is, despite Pt foil has a good signal until 20 A-1, it is usually used a smaller k-range (i.e. 3-12 A-1), right? I normally use a k-range of 3-12.
Analyze as far out in k as the data goes. It's usually pretty easy to tell when the noise in the data is larger than the signal. For room temperature data, it's often the case that the data stops around between 10 and 14 A^-1.
And finally, how to calculate bond distances from Reff and deltaR?
For single scattering paths, R = Reff + deltaR. --Matt