The role of electrodynamic interactions on energy loss intensities of adsorbed molecules

The effect on energy loss intensities of the electrodynamic interactions with the substrate and neighboring adsorbed molecules is discussed. The experimentally observed large variations in the loss intensity from molecules adsorbed on various sites are considered. A simple dipole model of the molecule interacting with its image in the substrate and its neighbors on equivalent and inequivalent sites is used. Good agreement with experiment for a well characterized surface coverage of bridge and on-top bonded CO molecules on Ni(111) is found.