Hi all, I just ran a feff calculation using feff6L and got a result that surprised me a little. I was modelling a ferrite with a nickel and boron substituted for iron in a small fraction of sites. Here's part of files.dat: file sig2 amp ratio deg nlegs r effective feff0010.dat 0.00000 2.706 2.000 3 3.7141 feff0011.dat 0.00000 26.472 20.000 3 3.7141 feff0012.dat 0.00000 4.038 2.000 3 3.7141 and the corresponding part of the paths.dat: 10 3 2.000 index, nleg, degeneracy, r= 3.7141 x y z ipot label rleg beta eta -3.126710 1.042240 1.042240 1 'Ni ' 3.4567 150.5039 0.0000 -1.146460 1.146460 1.146460 3 'O ' 1.9857 58.9923 0.0000 0.000000 0.000000 0.000000 0 'Fe ' 1.9857 150.5039 0.0000 11 3 20.000 index, nleg, degeneracy, r= 3.7141 x y z ipot label rleg beta eta 1.042240 -3.126710 1.042240 2 'Fe ' 3.4567 150.5039 0.0000 1.146460 -1.146460 1.146460 3 'O ' 1.9857 58.9923 0.0000 0.000000 0.000000 0.000000 0 'Fe ' 1.9857 150.5039 0.0000 12 3 2.000 index, nleg, degeneracy, r= 3.7141 x y z ipot label rleg beta eta -1.042240 3.126710 1.042240 4 'B ' 3.4567 150.5039 0.0000 -1.146460 1.146460 1.146460 3 'O ' 1.9857 58.9923 0.0000 0.000000 0.000000 0.000000 0 'Fe ' 1.9857 150.5039 0.0000 So here's the question. These three paths are identical except for the identity of one of the scattering atoms. The degeneracy of the path with boron and the path with nickel is the same. Why is the feff amplitude ratio for the boron-containing path higher than that of the nickel-containing path? Shouldn't nickel scatter more strongly? And yes, I double-checked...the potentials are defined correctly in the feff.inp file. --Scott Calvin Sarah Lawrence College