Normal Mode Analysis of Liquids

波士顿大学的托马斯凯斯得到了 理论和计算化学计划，继续他的工作， 过冷液体动力学性质的简正模分析。 简正波分析将用于计算内部 在二硫化碳和小烷烃中的自扩散振动， 振动动力学和液体中的模型化学品的寿命，以及 正丁烷中的扭转势垒穿越率。 该方法还将 可以用来解释振动寿命的温度依赖性。 凯斯计划发展飞秒光谱学的理论， 溶剂化动力学 理论结果将与分子 模拟和实验。 有很好的理论模型可以解释这种行为， 运动是混沌的气相系统的性质， 不频繁，相互作用很弱。 固体的理论模型 由于晶体中周期性排列， 系统提供了必要的简化， 解决方案 液体和过冷液体或玻璃的性质 仍然对理论解释提出了相当大挑战。 Keyes是 他是几位理论化学家之一， 从分子角度解释了 液体的性质。 这项工作的长期影响可能是 有助于理解凝聚态化学。

Thomas Keyes of Boston University is supported by a grant from the Theoretical and Computational Chemistry Program to continue his work on normal mode analysis of the dynamical properties of supercooled liquids. Normal mode analysis will be used to calculate the effect of internal vibrations on self diffusion in carbon disulfide and in small alkanes, vibrational dynamics and lifetimes of model diatomics in liquids, and torsional barrier crossing rates in n-butane. This methodology will also be used to interpret the temperature dependence of vibrational lifetimes. Keyes plans to develop a theory for femtosecond spectroscopy and solvation dynamics. Theoretical results will be compared with molecular simulations and with experiment. There are excellent theoretical models which explain the behavior and properties of gas phase systems where the motion is chaotic, collisions infrequent, and interactions are weak. Theoretical models for the solid state are also quite well developed since periodic order in crystalline systems provides the necessary simplifications to lead to tractable solutions. The properties of liquids and supercooled liquids or glasses still present quite a challenge to theoretical interpretation. Keyes is one of several theoretical chemists who is making significant headway on developing a molecular interpretation of the physical and chemical properties of liquids. The long range impact of this work could be significant in helping to understand chemistry in condensed phases.