Theoretical Studies of State to State Chemistry

理论和计算化学计划支持 Schatz的研究计划，该计划涉及使用计算 确定重要化学反应速率的方法 燃烧和大气化学。 对于某些反应， 当前这一代计算机为以下方面提供了新的机会： 使用理论来确定费率信息， 比实验强或者比实验强。 研究计划的一个目标是 因此，发展理论方法（量子和经典动力学 方法），利用新的计算机能力来表征 重要的反应。 这项工作的另一个组成部分是 确定力的势能面的表示 在反应发生时，原子之间的相互作用。 这些表面已经证明 当同时发生键断裂和键形成时， 或者当存在多个反应途径时发生。 然而，Schatz 小组开发了几种技术来表示这些表面 并且所得到的表面已被广泛使用。 理论动力学方法与反应势能 表面将一起用于研究几种特定的化学物质， 对燃烧和大气动力学感兴趣的反应 社区的目的是解释和预测实验。 计划的研究旨在了解试剂的作用 振动激发对化学反应性，包括重要性 模式特定的化学;在表征反应，其中有 反应发生时电子状态的变化（重点是 自旋-轨道激发对化学反应性的影响）;以及 理解没有反应路径连接的反应 试剂和产品。 其他主题包括使用理论， 理解化学反应过渡态的光谱学， 以及碰撞弛豫速率的表征， 反应中间体的稳定化。

The Theoretical and Computational Chemistry program is supporting Schatz's research program which is concerned with using computational methods to determine the rates of chemical reactions that are important in combustion and atmospheric chemistry. For certain kinds of reactions, the current generation of computers has opened up new opportunities for the use of theory to determine rate information at a level that is better than or competitive with experiment. A goal of the research program is therefore to develop theoretical methods (quantum and classical dynamics methods) that take advantage of the new computer power to characterize important reactions. Another component of this work is the representation of potential energy surfaces that determine the forces between the atoms while reaction takes place. Such surfaces have proven difficult to describe when simultaneous bond-breaking and bond-forming occurs, or when there are multiple reaction pathways. However the Schatz group has developed several techniques for representing these surfaces and the resulting surfaces have been widely used. The theoretical dynamics methods and reactive potential energy surfaces will together be used to study several specific chemical reactions of interest to the combustion and atmospheric kinetics community for the purpose of interpreting and predicting experiments. Planned studies are aimed at understanding the role of reagent vibrational excitation on chemical reactivity, including the importance of mode-specific chemistry; at characterizing reactions in which there is a change in electronic state while the reaction occurs (with emphasis on the influence of spin-orbit excitation on chemical reactivity); and in understanding reactions in which there is no reaction path that connects reagents and products. Other topics include the use of theory to understand the spectroscopy of transition states of chemical reactions, and the characterization of collisional relaxation rates that leads to the stabilization of reaction intermediates.