I was wondering if anyone can send any useful hints or tips for parameterizing a mixed multiple scattering shell comprised of two NaCl type strucutres, like the AgBr(1-x)Cl(x) example. Has anyone worked on fitting the third shell in that example? I am looking for examples of nacl rocksalt-like FEFF calculations that have successfully parametrized multiple scattering path contributions. Right now, after running feff, I'm using a different delr / ss term for each multiple scattering path I include. Does anyone have any clever ways of representing these in terms of the delr/ss in the first shell? Also, FEFF is telling me that the amp and mixing terms are almost completely correlated and this cause the amp term to blow up.