运用含时量子波包散射方法对H+OCl→OH+Cl反应体系的动力学研究-毕业论文(设计).docVIP

摘 要 分子碰撞和反应动力学是在分子原子水平上研究化学反应微观机理的一门科学，它不仅是宏观反应动力学的基础，同时也为解释化学反应中的基本现象提供了丰富的知识。作为分子碰撞和反应动力学最重要的理论方法之一。含时量子波包法已经成功用于氮原子-双原子气相反应散射领域，并在探索表面科学，费唐星散射以及水解过程等方面 也逐渐显示出重要作用。本文运用含时量子波包散射方法对H+OCl→OH+Cl反应体系进行了详细的动力学研究。 对H+OCl的体系的计算是在最近的从头计算势能面上展开的。分别计算得到了该体系的反应几率和速率常数。反应几率在整个的能量范围之内都比较大，且没有阈值。非常奇怪的是，计算得到的速率常数比已有的实验结果和理论结果大两个数量级左右，而在同一势能面上只通过共线路径计算得到的结果却和实验结果一致。为了找到引起偏差的原因，对反应的雅克比坐标中的θ进行了限制，得到的速率常数较好，大体与实验一致，通过详细分析势能面和动力学过程，发现夺取反应T构型势能面存在一个势阱，这个势阱可能就是引发计算结果与实验之间巨大偏差的原因 关键词:含时量子波包方法;分子碰撞和反应动力学;反应截面速率常数;从头计算势能面;势阱 ABSTRACT Molecular collision and reaction dynamics is a subject of studying microscopic mechanism of chemical reaction in molecular and atomic level. It can provide basic knowledge for interpreting general phenomena in the chemical reaction, and become the base of the macroscopic reaction dynamics. As One of the most important theoretical methods for molecular collision and reaction dynamics, time-dependent quantum wave packet method has been successfully applied in the gas phase atom-diatom reactive scattering and has played an important role in surface science, inelastic scattering and hydrolyzing investigation. In this paper, detail dynamics of H+OCl→OH+Cl system have been studied using the time-dependent quantum wave packet scattering theory . The calculation for H+OCl system are also carried out on the latest ab initio potential energy surface, the reaction probabilities and rate constants are all obtained. The calculated reaction probabilities ate relatively large in the whole energy range, and have no threshold energy .Very oddly, the obtained rate constants are about two orders of magnitude larger than previously experimental and theoretical results, whereas the previous theoretical results calculated only with collinear reaction configuration of the same PES are in accordance with experiment. In order to find the origin of the disagreement, calculations with limited angle θ in reactant Jacobi coordinates are performed again. The obtain rate const