Hi, Just wondering if anyone out there can help answer a few questions I have.... I've been using Ifeffit/Artemis to try and fit to some experimental spectra.... and in trying to determine the best fitting parameters (k-range, r-range etc.)... I've come across a few things I'm not quite clear on..... (1) I was wondering (this might be a silly question) whether it was considered inappropriate to fit over a range larger than your spectra? (i.e. k-range of fit set to 2-15 when in actuality the spectra data only goes to ~12.5?) (2) I don't quite understand the following the significance of the following statement: These are not yet computed quite right in all situations... Chi-square for this data set = 9.01156 R-factor for this data set = 0.01651 When previously in the results the Chi-square and R-factor were given as: Independent points = 11.272460938 Number of variables = 11.000000000 Chi-square = 4.505779601 Reduced Chi-square = 16.537341618 R-factor = 0.016508545 Measurement uncertainty (k) = 0.007252615 Measurement uncertainty (R) = 0.091026879 Number of data sets = 1.000000000 I'm confused by the different Chi-square values, and what values of Chi square and R-factor for the data set would Artemis be satisfied with? (3) Also is there anyway to have Artemis deternine the best k-range (or perhaps a way to have it step through different values of kmin and kmax) ? Just wishful thinking on my part probably... Please let me know if you can help me understand these issues a bit better. Thanks!!!!!! Kristine Witkowski Northwestern University