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.
