Dear all, I tried computing K-edge chi(k) for a solvated metal ion. For each snapshot, I simply carved out a cluster of radius 6 Ang around the metal. 1. if I set RMAX to say 5.5 in feff.inp, the chi(k) plot looks totally different from the case where the RMAX line is commented out (particularly k>10). I thought RMAX is the largest metal-H or metal-O separation but I think I am wrong 2. I dont quite understand why the number of paths increases (sometimes by a factor of 3) when I set RMAX as opposed to the case where I comment it out. 3. From time to time I get warnings indicating that a water O-H distance is too short: WARNING: TWO ATOMS VERY CLOSE TOGETHER. CHECK INPUT. atoms 5 7 5 0.14400 2.09700 1.16300 7 0.77400 2.67400 1.00800 I tried setting FOLP to 0.8 for H but the warnings persist. 4. On what criteria are sigma2 and s02 chosen? They are not usually reported in published theoretical papers and I was wondering if they are arbitrary. 5. Finally, is the chi(k) dependent of which version of FEFF is being used. I am asking this because the peak height of my FEFF6 chi(k) is slightly lower than that of published results using FEFF8. Thanks