Vibrational state of the chemisorbed molecule on metal surfaces: Role of electron-hole pair excitation

Publisher Website
Google Scholar
Abstract
A theory is presented to study the vibrational state of a molecule chemisorbed on a metal surface. The dynamical interaction between localized vibrational state and continuum of electron-hole pair excitations of the coupled molecule–metal system is found to be a dominant channel of vibrational energy dissipation of chemisorbed molecules, where the charge fluctuation in the molecular electronic states during a vibration plays an important role. The vibrational line shapes thus calculated are characterized by both large red shift in the frequency and very broad width (short lifetime) compared with those of free molecules, thereby showing a fairly good agreement with what was experimentally observed in conventional vibrational spectroscopy of chemisorbed molecules on transition metal surfaces.