Hello all, I would like to hear your opinion about reporting Chi^2 and R-factor values in EXAFS studies. I found that Chi^2 and R-factor values are not provided by many EXAFS papers. However, according to standards of The International XAFS Society (http://ixs.iit.edu/) both these values should be reported. My understanding is that the reduced Chi^2 should be close to 1 in ideal case. In practice however, the value is always greater than 1 because of systematic errors. For example, my reduced Chi^2 values are around 300. However, the R-factor values are about 3% which doesn't look as "ugly" as Chi^2 reduced. On the other hand, ifeffit overestimates uncertainties using reduced Chi^2 value. Thus, all errors are taken into account. The final question: Is it appropriate to report just R-factor calculated by ifeffit and the obtained uncertainties (which look reasonable) without reporting the "ugly" Chi^2/reduced Chi^2 values? Stanislav Stanislav Stoupin ----------------------------------- Research Assistant/PhD student BCPS department Illinois Institute of Technology email: stousta@iit.edu voice: 312-567-7983