This award supports Dr. Peter Winkler and a graduate student from the University of Nevada-Reno to collaborate with L .S. Cederbaum of the Department of Theoretical Chemistry at the University of Heidelberg. The collaboration will develop propagator theory for atomic and molecular structure calculations as well as for scattering problems. The research focuses on atomic calculations with a novel multi-channel propagator approach. The research is likely to lead to many interesting applications of the new formalism to the study of atomic processes in various environments. Working with the German group will give Dr. Winkler's group access to a considerable reservoir of knowledge and computational expertise.