Computer Simulation of Chemical Dynamics

William Hase 在理论和计算化学项目的支持下进行化学动力学计算机模拟领域的研究。该研究通过开发精确的理论模型来模拟分子内动力学、能量转移以及化学动力学和动力学来进行。 考虑了原子核的量子力学和经典处理。 此外，模拟基于经典势能表面和通过电子的量子力学处理确定的势能表面。后一种技术被称为直接动力学，其开发方式允许与其他现成的电子结构代码进行直接和系统的接口。 目前正在研究的问题包括质子化肽离子的表面诱导解离、臭氧在不饱和烃表面上的反应以及接近过渡态的分子内和单分子动力学理论。理解和控制化学反应的能力实际上影响着日常生活、经济和我们对生活本身的理解的各个方面。 化学反应发生在材料合成和原油精炼过程中。了解如何以最少的干预进行此类反应直接限制了产品的最终成本以及合成过程中产生的不需要的废料和/或热量的量。 从模拟臭氧与不饱和碳氢化合物表面相互作用中收集到的理解将直接转移到对流层中发生的类似过程。 在对流层中，此类过程会导致臭氧消耗，并会化学改变海洋有机气溶胶，从而直接影响云的形成和阳光向地球表面的传输。这里开发的计算方法依赖于精确的势能表面，因此为此目的直接与相关的量子力学方法耦合。 学生和博士后科学家通过网络以及研究人员的直接参与在课堂上接受培训。

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.