Dear Iffefit user I have a question about CFAVERAGE card used in FEFF8.4 for EXAFS simulations. I need to simulate a cluster with 1481 atoms, let's say in a first moment, composed of only Cu atoms. Without this card the simulations crashed and it was suggested to "Use or reduce rclabs in CFAVERAGE card Or increase parameter natx and recompile". I tried with different indexes: CFAVERAGE 1 -1 7 CFAVERAGE 0 -1 6... I could run EXAFS simulations but I could not get xmu.dat. FEFF8.4 works perfectly when <1000 atoms are involved (and CFAVERAGE is NOT used). But how could I simulate larger clusters (with more then 1000atoms)? Here I send you a copy of the feff.inp, I do not write here below all the atoms between the 1st and the 37th shell because I do not want to make this mail too large, but I attach the original file. TITLE A *cluster 1481 atoms CONTROL 1 1 1 1 1 1 PRINT 0 0 0 0 0 0 RMULTIPLIER 1 LDOS -30 20 0.2 EDGE K S02 1.0 SCF 4 0 30 0.2 1 NLEG 5 DEBYE 15 343 0 EXAFS RPATH 10.0 POTENTIALS 0 29 Cu 3 3 0.0010 1 29 Cu 3 3 1.0 ATOMS * this list contains 1481 atoms * x y z ipot tag distance 0.00000 0.00000 0.00000 0 Cu_1 0.00000 1.80753 1.80753 0.00000 1 Cu_1 2.55623 -1.80753 1.80753 0.00000 1 Cu_1 2.55623 1.80753 -1.80753 0.00000 1 Cu_1 2.55623 -1.80753 -1.80753 0.00000 1 Cu_1 2.55623 1.80753 0.00000 1.80753 1 Cu_1 2.55623 -1.80753 0.00000 1.80753 1 Cu_1 2.55623 0.00000 1.80753 1.80753 1 Cu_1 2.55623 0.00000 -1.80753 1.80753 1 Cu_1 2.55623 1.80753 0.00000 -1.80753 1 Cu_1 2.55623 -1.80753 0.00000 -1.80753 1 Cu_1 2.55623 0.00000 1.80753 -1.80753 1 Cu_1 2.55623 0.00000 -1.80753 -1.80753 1 Cu_1 2.55623 .... 3.61505 9.03763 -12.65268 1 Cu_37 15.96364 -3.61505 9.03763 -12.65268 1 Cu_37 15.96364 9.03763 -3.61505 -12.65268 1 Cu_37 15.96364 -9.03763 -3.61505 -12.65268 1 Cu_37 15.96364 3.61505 -9.03763 -12.65268 1 Cu_37 15.96364 -3.61505 -9.03763 -12.65268 1 Cu_37 15.96364 END Best Sebastiano Cammelli