With this grant in the Theoretical and Computational Program of the Chemistry Division, Professor Jackson will develop new methods for investigating the ways in which gas molecules behave on, and interact with, solid surfaces at finite temperatures. The PI will extend time dependent scattering theory to finite surface temperatures, thereby allowing for a better connection to be made between theory and experiment. The gas molecule and the surface and bulk vibrations are evolved self consistently and in a fully quantum manner, so that both one-phonon and multiphonon interactions can be described. The dependence of atom- and diatom-metal sticking probabilities on the properties of the gas particle, the solid, and the gas-surface interaction will be studied.