Michael Herman is supported by a grant from the Theoretical and Computational Chemistry Program to continue his development of improved semiclassical dynamical methods for treating vibrational relaxation in condensed phases. A series of studies will be undertaken to improve the accuracy and flexibility of semiclassical propagator methods for systems displaying quantum chaos. Herman has developed new integral conditioning methods that analytically account for the local phase cancellation inherent in semiclassical approaches. Further improvements in the approach will be developed for problems involving transitions between molecular quantum states. Applications involve semiclassical treatments of vibrational energy relaxation in condensed phases and clusters. Systems to be treated include a number of small molecules such as diatomic iodine anion in various solvents and in carbon dioxide clusters.
Since most chemical reactions of commercial importance occur in the condensed phase, it is important to understand the effect that solvation has on these processes. The theoretical treatment of such systems is complicated by the large number of degees of freedom involved, and any approach to treating such systems needs to be based on some level of approximation. Herman has developed a semiclassical approach for treating the dynamics of such systems that provides important molecular insights into the influence of solvation.
