Nancy Makri is supported by a grant from the Theoretical and Computational Chemistry Program to continue her research in the development of propagator path integral methodology. Makri is using this theory to treat systems with few quantum degrees of freedom in a heat bath where the bath degrees of freedom can be treated classically. This is accomplished by expanding the time evolution operator in truncated basis sets and results in propagators that are valid over large time increments and which do not suffer from the usual highly oscillatory behavior. Proposed applications include hydrogen transfer reactions in (and on) solids, tunneling, and non-adiabatic hopping probabilities of quantum particles. A great deal of progress has been made in the theoretical treatment of gas phase chemical reactions of systems consisting of relatively few atoms. Using state-of-the-art theoretical methods, it is now possible to explain a great deal of the experimental detail for such systems. However, the large majority of reactions which are of interest to chemists occur in condensed phase systems in the presence of solvent. The theoretical models for treating such complex systems are in a much earlier stage of development. Makri is developing new theoretical approaches for dealing with solvated chemical systems undergoing chemical reactions where quantum effects may be important.
