优化的准量子理论研究惰性原子与NO分子的碰撞转动激发问题

Studying energy transfer in interactions between atoms and molecules is vital to our understanding and controlling of molecular reaction dynamics processes. Rotational excitation in atomic-molecular collisions is a focal point in this area. This project is aiming to explore and develop an advanced Quasi-Quantum Treatment (QQT) method, which is based on quantum interferences between different orientations of the potential, for researching the inelastic collision mechanism. Instead of the more complicated partial wave expansion approach in fully quantum calculation, QQT uses a kind of Feynman path integral method that exploits the path length differences originating from the different orientations of an anisotropic molecule. As a result, the QQT provides valuable physical insight while requiring very little computational effort. The state-to-state resolved angular distribution of the scattered products, characterized as the differential cross sections (DCSs), describes how the molecules are scattered in space after collision, constitutes one of the most detailed of all dynamical events. In this project, we proposed to extend the QQT theory from spin-orbit state conserving transitions to the spin-orbit state changing transitions. Moreover, the hard shell potential will be modified to a softer shell. These will definitely improve our ability to explore the rich structure information within the collision dynamics. The QQT method is still a blank space of study in our country. The development of this theory will not only help us to get deeper understanding of the dynamic mechanism of collision-induced molecular energy transfer, but also benefit the subject construction in this area.

研究原子与分子相互作用中的能量转移对探索和控制分子反应动力学过程至关重要，碰撞诱导转动激发是此领域的焦点问题之一。本项目旨在发展一种基于量子干涉效应研究中性原子与分子碰撞转动激发的先进准量子理论，该理论从费曼路径积分思想出发，在量子态分辨水平上计算态-态微分散射截面，研究产物的能量分布和角度分布，可以获取丰富的碰撞动力学信息，在探明量子效应的同时兼具计算时间短、物理含义清晰等优点。本项目以惰性原子He/Ar/Ne与开壳层NO分子的碰撞体系为研究对象，以拓展准量子理论到自旋-轨道态变换跃迁及优化体系势能面到软壳近似为目标，通过提升该理论处理碰撞转动激发问题的广度和精度，更细致了解碰撞体系相互作用势的演化规律。准量子理论在国内尚无研究工作开展，该理论的推进对深入研究碰撞转动传能过程中的动力学机制具有重要意义。

原子与分子碰撞转动激发是研究碰撞诱导能量转移的基本问题，在燃烧、天体物理、大气及超冷化学等多个领域具有重要意义。本项目旨在发展一种先进的准量子理论，用于探索原子与分子相互作用中的碰撞动力学机制。以经典的NO-He碰撞体系为研究对象，首次将准量子理论拓展到自旋-轨道态变换跃迁，通过计算态-态微分散射截面，深入地研究了势能面对分子碰撞机制的影响。同时，通过更细致的模拟分子散射路径，将之前准量子理论采用的硬壳势能面优化到软壳近似，有效提升了微分散射截面的计算精度，从而获取了分子碰撞过程中更加准确的动力学信息。此外，在项目支持下，首次采用全量子理论研究了双原子分子H2-O2碰撞的转动激发问题，计算了H2分子在顺磁分子O2作用下从仲氢到正氢的转化速率，理论结果与实验数据符合的很好。此部分工作在核磁共振及医疗诊断方面具有重要指导意义。