Spectral line shapes in dissipative systems: Molecules adsorbed on metal surfaces

A physical situation of adsorption of molecule adsorption on a metal surface on excitation by light was considered. The temporal evolution of rates and probabilities of transitions were derived for a Hamiltonian. These tansitions were induced by light between states of a molecule interacting with a dissipative medium. The rates and probabilities from perturbation theory were obtained by biorthonormal basis set of decaying eigenstates. Continuous and pulsed light was used to develop the formalism for excitation.S.M.A. has been partly supported by the DGICYT (Spain) under Contract No. PB95-0071 and gratefully acknowledges the support by the QTP at the University of Florida during his stays.Peer Reviewe