William Hase is supported by the Theoretical and Computational Chemistry Program to perform research in the area of computer simulation of chemical dynamics. The research proceeds by development of accurate theoretical models for simulations of intramolecular dynamics, energy transfer, and chemical dynamics and kinetics. Both quantum mechanical and classical treatments of the nuclei are considered. Further, simulations are based on both classical potential energy surfaces and those determined from quantum mechanical treatments of the electrons. The latter technique, referred to as direct dynamics, is being developed in a way that allows for direct and systematic interfacing with other off-the-shelf electronic structure codes. Problems currently being studied include surface induced dissociation of protonated peptide ions, reaction of ozone on unsaturated hydrocarbon surfaces and the theory of intramolecular and unimolecular dynamics for approaching transition states.
The ability to understand and control chemical reactions impacts practically every aspect of daily life, the economy and our understanding of life itself. Chemical reactions occur during synthesis of materials and during refinement of crude oil. Understanding how to make such reactions proceed with minimal intervention directly limits the ultimate cost of the product and the amount of unwanted waste materials and/or heat that are generated during synthesis. Understanding gleaned from simulation of ozone interactions with unsaturated hydrocarbon surfaces will be directly transferable to analogous processes that occur in the troposphere. In the troposphere, such processes lead to ozone depletion and also chemically alter oceanic organic aerosols that directly affect the formation of clouds and the transfer of sunlight to the surface of the earth. The computational methods developed here rely on accurate potential energy surfaces and are therefore coupled directly to relevant quantum-mechanical methods for such purposes. Students and postdoctoral scientists are trained in the classroom, via the web, and by direct participation with researchers.
