Vibrational linewidth of CO adsorbed on Pt(111)

Abstract

We show that vibrational spectra of molecules chemisorbed on metal surfaces can be affected by anharmonicity much more than usually estimated if various vibrational coordinates are coupled by non-diagonal terms. The strong coverage dependence of the linewidth of the adsorbate-metal vibrations of CO adsorbed on Pt(111) can be attributed to the multiphonon decay, enhanced by a strong coupling of the adsorbate motion to the in-plane displacement of the surrounding surface atoms. © 1995.