Dear Professor "Matt Newville The first I would like to thank for your mails sent me on Tue Mar 22, 2011 and On Sun, Mar 27, 2011. Now, I have had success for entering to ifeffit@millenia.cars.aps.anl.gov My new questions are: 1) Should I introduce in GDS degen parameter for fitting beside amp, enot, delr and ss? What happened when I want to obtain coordination number (CN) associated to some coordination shell. I thank that there is a difference some time between CN and degen. In some cases they are the same. Many journals as you know report CN. For a coordination shell I think that we have some times more paths, is it rue or false? Does dgen associate only for a path ? 2) I could to view the feffXXXX.dat in according with your indication in own folder of computer package program c:\Document andSettings\USERNAME\Application Data\horae\stash, but can I save directly them? I did not find a direct bottom for saving them, is it true or I did not see it? 3) The exafs signal is a real function from math. point of view. So, FT[chi(k)]= real_RDF_even(r)+i*RDF_odd(r). Then IFT[real_RDF_even(r)+i*RDF_odd(r)] = chi_real(k)+ i*zero, where i=sqrt(-1), is it true ? In affirmative case why you have in ARTEMIS plot region the both components ? Is not the imaginary part zero ? from math p. v. the module of chi(r) is a symmetrical signal. Even, we take into account only a region [rmin:rmax] for RDF(r) we obtain for IFT of RDF(r) only a real signal. Thanking you I advance I remain, Nick Aldea