Lifetime broadening of excited pyrazine adsorbed on Ag(111)

High-resolution electron-energy-loss spectroscopy has been used to study the vibrational broadening in the B2 u1(, *) excited state of pyrazine adsorbed on Ag(111). Strong lifetime broadening of ~100 mV for the first and ~20 mV for the second pyrazine layers are determined. These lifetimes are in reasonable agreement with those predicted by classical theory. © 1981 The American Physical Society.