Modern Approaches to Gas-Phase Quantal Molecular Reactions

纽豪泽大学9314320号卡尔。洛杉矶这个硅藻-硅藻反应散射理论的项目得到了美国国家科学基金会理论和计算化学计划的支持。对于双原子分子的气相反应，将进行精确的耦合通道、态对态、量子散射计算，并显式考虑所有六个内部自由度。将开发改进的计算方法，特别是利用吸收势的依赖于时间的和等价的与时间无关的通量-幅值方法，以及用于精确计算特征值位于选定范围内的特征向量的改进的滤波算法。该理论的第一个应用将是分子氢与羟基自由基的反应。这个研究项目开发了改进的计算方法来预测一个非常简单的化学反应的详细行为。将对一个四原子系统进行严格的量子力学计算。其目标是获得发生的原子事件的详细和准确的图像。这一基础知识从激光光谱学和其他实验室实验中提取是困难和昂贵的，它提供了详细的信息，用于测试用于大分子气相反应实际计算的各种简化数学近似。分子氢与羟基自由基的反应本身是很有意义的，因为它是氢气燃烧过程中发生的链式反应中的重要一步。

9314320 Neuhauser Univ. Cal. Los Angeles This project in diatom-diatom reactive scattering theory is supported by the NSF Theoretical and Computational Chemistry Program. Exact, coupled-channel, state-to-state, quantum scattering, calculations will be carried out for gas phase reactions of diatomic molecules taking explicit account of all six degrees of internal freedom. Improved computational methods will be developed, in particular, a time-dependent and an equivalent time-independent flux-amplitude method, use of absorbing potentials, and an improved filter algorithm for the accurate computation of eigenvectors whose eigenvalues lie within a selected range. The first application of the theory will be to the reaction of molecular hydrogen with the hydroxyl radical. This research project develops improved computational methods for predicting the detailed behavior of a very simple chemical reaction. Rigorous quantum mechanical calculations will be carried out for a four-atom system. The goal is to obtain a detailed and precise picture of the atomic events that occur. This fundamental knowledge, which is difficult and expensive to extract from laser spectroscopy and other laboratory experiments, provides detailed information that serves to test various simplifying mathematical approximations used for practical calculations for gas phase reactions of larger molecules. The reaction of molecular hydrogen with the hydroxyl radical is itself of interest because it is an important step in the chain reaction that occurs during the combustion of hydrogen gas.