姜-泰勒效应的发展及其在与大气和星际相关瞬变物种结构和稳定性中的应用

Jahn-Teller effect is one of the most fascinating phenomena in modern physics and chemistry with comprehensive applications in molecular spectroscopy, stereochemistry, structural phase transitions, solid-state physics, high-temperature superconductivity etc. However, the possible influence of pseudo Jahn-Teller effect in systems for which the proper Jahn-Teller effect may be expected to be active as well as species exhibiting the Renner-Teller effect was underestimated and even ignored by traditional Jahn-Teller effect theory. We will concern ourselves on simultaneously treating the two effects (PJTE and RTE, or PJTE and JTE) in molecules or radicals by considering all the relevant electronic states which produced PJTE, formulating and solving the secular equation, and calculating their respective coupling parameters by computer program and ab initio calculations, and finally obtaining their respective contribution for molecular stability. It will be very helpful for the development and innovation of Jahn-Teller effect theory. In addition, the theory will be applied in studying the structure and stability of the active radicals and molecules which are interesting in atmosphere and interstellar chemistry, revealing their Jahn-Teller origin, explaining the experimental finding, and providing valuable theoretical prediction for further experimental study.

姜-泰勒效应是现代物理和化学领域里最重要的现象之一，在分子光谱，立体化学，结构相变，凝聚态物理，高温超导材料等领域有广泛的应用。然而，对传统上认为仅含有Renner-Teller Effect (RTE)或Proper Jahn-Teller Effect (JTE)效应的体系，Pseudo Jahn-Teller effect (PJTE)对分子结构和稳定性的影响往往被低估甚至忽视。本项目拟在RTE或JTE基础上加入PJTE的耦合作用，实现对同一体系所涉及的两种姜-泰勒效应类型同时处理，并建立久期方程、且编写相应程序实现数值解，进一步计算振动耦合常数，揭示PJTE对分子结构和稳定性的影响。这是在姜-泰勒效应理论上的拓展和创新，并且将该理论应用于与大气和星际相关的瞬变物种的研究，阐明其结构和稳定构型形成的姜-泰勒效应来源，解释实验现象，为实验研究提供可靠的理论依据。

本项目从理论和应用两个方面发展了姜-泰勒效应理论，研究内容基本上都按计划进行，达到了预期的研究目标。通过对与大气和星际相关的一系列分子体系的研究，获得了较精确的姜-泰勒效应振动耦合常数；合理的阐明了赝姜-泰勒效应与分子结构和电子态能级的关系，并应用该关系预测了一些新的硅/锗类化合物（半导体材料前身）的稳定结构，为实验研究提供了可靠的理论依据。除此之外，我们在研究中发现了由赝姜-泰勒效应引发的“圆柱对称性畸变”现象，这是本研究计划预料之外的一个可喜的发现。作为一种新奇的对称性破缺现象，该发现将丰富人们对分子空间几何结构和对称性的深入认知。