Theoretical and Computational Chemical Dynamics and Energetics

点击翻译按钮获取中文摘要

Donald Truhlar is supported by a grant from the Theoretical and Computational Chemistry Program to continue his work on chemical dynamics and energetics. Three areas of research are proposed: 1) development of an improved theoretical framework for the analysis and prediction of photochemical reactions; 2) development of improved methods for treating quantum dynamical effects in condensed-phase chemical reactions; and 3) improved methods for the quantum mechanical treatment of the properties and dynamics of small clusters. Major objectives of the research include: 1) To analyze the accuracy of trajectory surface hopping algorithms for electronically nonadiabatic chemical reactions by testing them against converged quantum dynamical results to be produced by his new linear algebraic variational methods; 2) To pinpoint the specific features of trajectory surface hopping methods that are most responsible for any observed inaccuracies and to use this knowledge to focus future efforts to improve the methods; 3) To develop a transition-state-theory-like approximation for overall quenching rate constants; 4) To better understand the physical effects that determine branching ratios for decomposition of exciplexes through funnels; 5) To incorporate quantum mechanical effects into practical variational transition state theory calculations; 6) To further develop the stabilization method as a practical tool for multi-dimensional resonances; 7) To exploit parallel computers for efficient quantum mechanical calculations on four-body systems; and 8) To use the accurate quantum dynamical calculations on hydrogen fluoride dimer as a means of improving the potential energy surface for this system. Truhlar's research is aimed at a basic molecular level understanding of chemical dynamics and solvation. This research has important strategic implications in areas of atmospheric and environmental chemistry.