Theoretical Descriptions of Rotation-Vibration Interactions In Polyatomic Molecules

在这个项目的理论和计算程序， 在化学系，西伯特教授将进行一套 旋转振动的完全量子力学计算 多原子分子的状态。对这些状态的了解是 来预测化学反应的速率。 计算将包括广泛的分子使用 变分和微扰技术。的目标 计算是为了阐明 玻恩-奥本海默势能面和动力学， 光谱，这是由于这些运动发生的结果， 表面。待处理的系统将包括H2O、SO2、HCN， HCCH、NH3和H2 CO。坐标和基集表示 将开发不仅便于计算 给定势能面的光谱，但也是相反的， 也就是说，势能面的计算给出了 谱选择用来描述 振动分子将被特别设计， 描述某些大振幅运动， 坐标不够。了解这些 转型在我们的能力中起着关键作用， 理解和发展反应速率，反应 动力学、碰撞能量转移和模式特异性 方面的影响.

In this project in the Theoretical and Computational Program of the Chemistry Division, Professor Sibert will carry out a set of fully quantum mechanical calculations of rotation-vibration states of polyatomic molecules. A knowledge of these states is necessary to predict the rates of chemical reactions. The calculations will encompass a wide range of molecules using both variational and perturbative techniques. The goal of the calculations is to elucidate the connections between Born-Oppenheimer potential energy surfaces and the dynamics and spectroscopy, which occurs as a result of motion on these surfaces. The systems to be treated will include H2O, SO2, HCN, HCCH, NH3, and H2CO. Coordinate and basis set representations will be developed which facilitate not only the calculation of spectra given a potential energy surface, but also the inverse, namely, the calculation of potential energy surfaces given the spectra. The representation chosen to describe the rotating-vibrating molecules will be specifically designed to describe certain large amplitude motions for which Jacobi coordinates are inadequate. An understanding of these transformations plays a pivotal role in our ability to understand and develop theories of reaction rates, reaction dynamics, collisional energy transfer, and mode specific effects.