With this grant in the Theoretical and Computational Program of the Chemistry Division, Professor George will perform theoretical studies of the elementary excitations of atoms and molecules coupled to a host matrix, which is either a solid or a cluster. This work is critical in understanding the important experimental data gathered in this area. A formal theory will be developed to describe the dynamics of molecular exciplexes coupled to elementary excitations of a solid matrix; i.e., quasiparticles such as phonons. This theory will incorporate electron-phonon interactions and the effects of spontaneous emission between phonon-shifted electronic states. A semiempirical approach called the diatomics-in-ionic-systems (DIIS) method will be used to study the structure of neutral and positively charged rare gas clusters containing hydrogen and/or halogen species. Special attention will be given to the case of argon cluster. This study will also involve the calculation of excited as well as the ground electronic states.
