Modern Approaches to Gas-Phase Quantal Molecular Reactions

9314320诺伊豪泽加州大学洛杉矶这个硅藻反应散射理论的项目得到了NSF理论和计算化学计划的支持。 精确的，耦合通道，状态到状态，量子散射，计算将进行气相反应的双原子分子，明确考虑所有六个内部自由度。 将开发改进的计算方法，特别是依赖于时间的和等效的不依赖于时间的通量-振幅方法，使用吸收势，以及用于精确计算特征值在选定范围内的特征向量的改进的滤波器算法。 该理论的第一个应用是氢分子与羟基自由基的反应。 该研究项目开发了改进的计算方法，用于预测非常简单的化学反应的详细行为。 将对四原子系统进行严格的量子力学计算。 目标是获得发生的原子事件的详细和精确的图片。 从激光光谱学和其他实验室实验中提取这一基础知识是困难和昂贵的，它提供了详细的信息，用于测试用于较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令人感兴趣的，因为它是在氢气燃烧期间发生的链式反应中的重要步骤。

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.