Michael F. Herman of Tulane University is supported by the Theoretical and Computational Chemistry Program to continue work in designing accurate semiclassical methods to study complex systems undergoing quantum transitions. These methods are improving the numerical efficiency of semiclassical schemes, which is allowing them to be applied to more realistic physical systems. Developments underway include extending the family of surface hopping methods by providing a solid theoretical basis for their implementation, developing an Initial Value Representation (IVR) based on classical molecular dynamics, and delineating a hierarchy of approximations to create opportunities for applications to a broad range of problems. These methods will allow studies of more larger and more complex systems with greater accuracy, efficiency and reliability. Applications include models of the relaxation of vibrational energy of molecules in liquids, and electron transfer from a donor system to an acceptor system in the condensed phase. This work is having a broader impact in training undergraduates, graduate students and postdoctoral associates in chemical physics theory and computational methods. The methods developed in this work are providing versatile tools that will find application in a variety of fields.
