Hi Matt, OK, I got the point and it is clear now. Thanks Pawel

As you've probably read in the Feff documentation, Feff has a couple of filters that it uses: one fast and less accurate to eliminate really unimportant scattering paths to make the path-finding mechanism more efficient, and one slightly more accurate one to decide later which paths to calculate the EXAFS for. At this point, both of these optimizations seems less-than-critical, and just turning them off completely (CRITERIA 0 0) is not so bad, especially for moderately ordered systems like your crystal structure.