Studies in Molecular Theory (Chemistry)

分子理论研究（化学）

• 批准号: 8713564
• 负责人: C. Alden Mead
• 金额: $ 7.75万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-09-01 至 1990-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8713564&HistoricalAwards=false
• 关键词: Studies; Molecular; Theory; Chemistry

This project is funded under the Theoretical and Computational Chemistry program. The work involves questions of fundamental theory of how the energy of a molecular system changes when the positions of the nuclei are varied. The consequences of these changes can be quite subtle but still detectable experimentally, and properties of small clusters of alkali metal atoms are expected to be explained by the theoretical developments to be undertaken. In more detail, earlier work on the implications of conical intersections between Born-Oppenheimer potential energy surfaces is to be extended in several directions. Such intersections produce anomalous sign changes in electronic wave functions when the nuclear coordinates traverse a closed path around the intersection. The past results on the effect of permutation symmetry for three and four identical nuclei are extended to the general case. Professor Mead will study the generalization to phase changes and unitary transformations experienced by electronic wave functions representing Kramers doublets when the nuclear coordinates traverse closed paths, and the analogy with gauge field theories of elementary particles. He will also obtain general functional forms for potential energy surfaces and derivative couplings for various systems. The nonremovable derivative coupling, which cannot be transformed away by going to a diabatic basis, will be further studied, and the question of whether there are specific effects which can be attributed to it will be explored.

该项目由理论和计算 化学课程。 这项工作涉及到一些基本的问题， 一个分子系统的能量如何变化的理论， 原子核的位置是变化的。 这些后果 变化可能非常微妙，但仍然可以检测到 实验上，小团簇碱金属的性质 金属原子有望被解释的理论 要进行的发展。 更详细地说，早期的工作对圆锥的影响， 玻恩-奥本海默势能 表面将在几个方向上延伸。 等 交叉点产生电子波的异常符号变化 当核坐标遍历闭合路径时， 在十字路口附近。 过去的结果对效果的影响 三个和四个相同核的排列对称性是 扩展到一般情况。 米德教授将研究 相变和幺正变换的推广 代表克莱默斯的电子波函数 当核坐标穿过闭合路径时， 与初等规范场论的类比 粒子 他还将获得一般的函数形式， 势能面和导数耦合 系统. 不可移除的衍生耦合，其不能被 转变为非绝热基础， 研究，以及是否有具体的影响， 这可以归因于它将被探讨。