Electronic Damping of Adsorbate Vibrations on Metal Surfaces

First-principles calculations of the vibrational lifetime of atomic and molecular hydrogen adsorbed on metal surfaces due to excitation of electron-hole pairs in the substrate are reported. The calculated electronic contribution to the vibrational linewidth compares favorably with experimental observations. A correlation is demonstrated between enhanced damping rate and the passage of an adsorbate-induced resonance through the Fermi level.