Dear Daria, as you stated the fitting result is very similar for the smoothed and unsmoothed data. So I think the answer to some commenters' question "Why do you smooth the data?" is that it just looks better. First of all, if you smooth your data you must, obviously, say so and explain how you did the smoothing when publishing/presenting these results. Secondly, the quality of the raw EXAFS data is an important measure of how good the measurement is. Smoothing it will remove this information. This is a strong argument to NOT use smoothing. When you do Fourier-Transformation from k-space to R-space (and possibly back from R-space to q-space) this automatically smooths the data. I am aware that this is a filtering of frequencies rather than "real" smoothing, but it will give the effect you want: The data will look less noisy. In conclusion, I would suggest never smoothing, instead showing the back-transform from R-space to q-space if you want to have nice looking curves but your data are not that good but ALWAYS supplying raw data in publications. With kind regards, Felix -- Dr. Felix E. Feiten Fritz-Haber-Institut der Max-Planck-Gesellschaft Department of Interface Science Faradayweg 4-6 14195 Berlin phone: +49 30 8413 4142