Hi everyone, I doing LCF on my XANES data. I wonder if someone can tell me the meaning of the values in parentheses following the weight value in the Fit results window?. I looked into the respective document section of the Manuel but could not find the answer, yet. I am asking because I did a Fitting with over 20 standards (STD) to find all combination of max 4 standards which describe my unknown sample spectra. This results in a lot of combination with similar chi-square(reduced) and R-values. I know a relative changes between these values are more probably meaningful than absolute values. A lot of the possible combinations provided by after the fit yieled combinations with at lest on STD having a weight of 0.000. (Fit 1). I thought that this would mean, that 3 standards are sufficient to describe the system. However, repeating the fit with only the three standards with weight > 0.0 yielded a complete different proportions (Fit 2). How can this be explain and how should I deal with combinations or standards having a weight of 0.000? Thanks a lot for your thoughts and suggesting, Cheers Paul *Results **Fit 1:* 3: STD3 0.324(0.025) 7: STD7 0.686(0.021) 20: STD2O 0.127(0.016) 27: STD27 0.000(0.036) vs. *Results Fit 2:* 3: STD3 0.473(0.019) 7: STD7 0.620(0.023) 20: STD20 0.000(0.030)