Simulation Studies of Many-body Dynamics in Liquids

威廉·斯蒂尔教授得到了理论和计算化学计划的资助，负责对液体中的多体动力学进行计算机模拟。所提出的计算对于理解分子在液体中的运动以及这种运动对观察到的红外、拉曼和去偏振光散射光谱的影响是重要的。基于真实分子间相互作用势的计算机模拟将被用来给出实际分子的表示，选择这样的表示以便实验数据可用于比较。要研究的性质取决于组成液体的分子的平移和旋转运动。这些性质包括：远红外光谱和近红外光谱；拉曼光谱和去偏振光散射光谱；热输运系数；以及核自旋偶极-偶极弛豫时间。理论表明，这些现象涉及二体、三体和四体的动力学贡献。斯蒂尔建议研究这些多体因素中每一个的相对大小和时间尺度。被建议研究的分子范围从简单的分子，如一氧化碳，到相对复杂的分子，如苯甲酸乙酯，在分子内重新定向和全分子运动之间存在竞争。

Professor William Steele is supported by a grant from The Theoretical and Computational Chemistry Program to perform computer simulations of many-body dynamics in liquids. The proposed calculations are important as an aid to understanding molecular motion in liquids and the effects of this motion on the observed infrared, Raman, and depolarized light scattering spectra. Computer simulations based on realistic intermolecular interaction potentials will be employed to give representations of actual molecules, chosen so that experimental data are available for comparison. Properties to be studied depend on the translational and rotational motion of the molecules which composed the liquids. These properties include: far and near infrared spectra; Raman and depolarized light scattering spectra; thermal transport coefficients; and nuclear spin dipole-dipole relaxation times. Theory indicates that these phenomena involve two-, three-, and four-body dynamical contributions. Steele proposes to study the relative magnitudes and timescales for each of these many-body contributing factors. Molecules proposed for study range from simple molecules such as carbon monoxide up to relatively complex ones such as ethyl hexyl benzoate where there is competition between intramolecular reorientation and whole-molecule motions.