This is in response to Shelly's post for MS references.  For linear multiple scattering, I like to use this paper:     Hudson, EA; et. al. (1996) Phys Rev B 54(1) 156-165 It uses the uranyl ion specifically in this example and has a short section in the introduction about the relations between single and multiple scattering D-W parameters. Hope this is vaguely what you were looking for....     Sam