Matt & IFEFFIT group, This is actually a feff.inp question.... but I'm hoping someone might be able to clarify this for me... I was wondering what appropriate values are for l_scmt, l_fms, and stoichiometry for the feff.inp I'm working with regarding Au on a Ni surface (I'm fitting with feff calculations with either a single Au atom in the first Ni layer or two Au atoms in the first Ni layer)? Should they all be the same for each potential? I just wanted to check if my values were appropriate. I've used some values based off of an example file all along... but I'm not sure if I used them appropriately for my scenerio. I've read the FEFF8.10 manual but I'm still unclear as to the proper values... (i.e. in the past I have used the following for 2 Au's in the surface) POTENTIALS * ipot z element l_scmt l_fms stoichiometry 0 79 Au 3 3 0.001 1 28 Ni 2 2 4 2 79 Au2 3 3 4 Oh... one more question... I haven't been using the ellipticity card in the feff.inp file, even though I've been using "POLARIZATION 1 0 0"... is this OK? Thanks, Kristine