Path integral and semiclassical approaches to the dynamics of large chemical systems

Nancy Makri 得到了理论和计算化学项目的资助，继续她对大型化学系统动力学的路径积分和半经典方法的理论研究。 Makri 将使用影响函数方法来研究复杂多原子环境中系统的量子动力学。 她将利用影响函数的结构，允许正向和反向时间演化算子配对。 这导致了适合蒙特卡罗积分的表达式。 将研究两个程序：1）溶剂势的局部二次、瞬时简正模展开； 2）影响函数的严格半经典前向-后向初始值表示。 Makri 计划对团簇和流体中的能量传递动力学进行基准计算和应用。化学家感兴趣的绝大多数反应发生在溶剂存在的凝聚相系统中。 处理此类复杂系统的理论模型仍处于发展的早期阶段。 Makri 正在开发新的理论方法来处理正在经历化学反应的溶剂化化学系统，其中量子效应很重要。

Nancy Makri is supported by a grant from the Theoretical and Computational Chemistry Program to continue her theoretical research on path integral and semiclassical approaches to the dynamics of large chemical systems. Makri will use an influence functional approach to study the quantum dynamics of a system in a complex polyatomic environment. She will exploit the structure of the influence functional that allows pairing of the forward and reverse time evolution operators. This leads to expressions amenable to Monte Carlo integration. Two procedures will be investigated: 1) a locally quadratic, instantaneous normal mode expansion of the solvent potential; and 2) a rigorous semiclassical forward-backward initial value representation of the influence functional. Makri plans to conduct benchmark calculations and applications to the dynamics of energy transfer in clusters and fluids.The large majority of reactions that are of interest to chemists occur in condensed phase systems in the presence of solvent. The theoretical models for treating such complex systems are still in the early stage of development. Makri is developing new theoretical approaches for dealing with solvated chemical systems undergoing chemical reactions where quantum effects are important.