Lifetimes of electronically adiabatic vibrational states of a chemisorbed atom

Abstract

A Green function formalism is introduced to deal with the non-adiabatic coupling of a chemisorbed atom with a metal. Starting from the Born-Oppenheimer system of coupled equations, general formulae for the phonon relaxation rate, and the energy renormalization on an electronically adiabatic potential energy curve have been obtained. This theory is applied to the Grimley-Pisani model of chemisorption. Numerical results for a linear atomic chain with one adatom, and for a cluster model, by treating the motion of the adatom in the harmonic approximation, are presented.