New Methods for Incorporating Quantum Mechanics in the Treatment of Complex Reactive Dynamical Systems

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

Donald Truhlar of the University of Minnesota- Twin Cities is supported by an award from the Theory, Models and Computational Methods program to develop methods for simulating complex, reactive dynamical systems in chemistry and for applying these methods to diverse systems. A focus of the research is the development of techniques to incorporate quantum mechanical effects in complex system. A key issue that the research addresses is the interface of electronic structure theory and dynamics. The PI and his research group are developing new approaches for efficiently computing potential energy surfaces and coupling terms in a manner that is practical for complex simulations. They are devising many novel methods including new ways to combine quantum mechanics and molecular mechanics, new methods for the diabatic representation of electronic states for use in dynamics calculations on photo-induced processes, new approaches to calculating the nuclear motion in coupled-state dynamics, new approaches to fitting coupled potential energy surfaces, and novel ways to model the participation of enzyme or other environmental coordinates in the reaction coordinate. The long range objectives of this research involve (i) calculation of branching ratios for photochemical reactions, (ii) simulation of atmospheric nucleation processes and (iii) calculation of the rate constants, kinetic isotope effects, and temperature dependence of the rate constants for reactions catalyzed by enzymes. These research areas are of enormous technological importance especially for health, the environment, the material needs of society, industrial competitiveness and defense