Interactions Between Molecules and Solids: I. The Vibrational Lineshape of Matrix Isolated Diatomics. I. Electrodynamic Interactions Between Molecules and Metal Surfaces.

As indicated in the title, this dissertation will be presented in two sections. Though seemingly unrelated, the work of both sections is directed at studying the role that the collective modes and excitations present in solids play in such processes as energy transfer and relaxation when molcules are in contact with a many-body system. In Part I the role of phonons in the vibrational relaxation of matrix isolated diatomics is studied. The vibrational lineshape for CO isolated in a noble gas lattice is computed in order to gain insight into how a vibrationally excited molecule relaxes towards equilibrium. In Part II the role the electron gas of a metal plays in the interaction with and between adsorbed molecules is examined using a jellium, infinite barrier, R.P.A. model. The way in which electron -hole pair and surface plasmon excitations affect such processes as the fluorescent lifetime and shift and the thermal desorption rate of adsorbed molecules is studied.