Prediction of electronic excited states of adsorbates on metal surfaces from first principles

We present the first ab initio prediction of localized electronic excited s tates in a periodically infinite condensed phase, a heretofore intractable goal. In particular, we examined local excitations within a CO molecule ads orbed on Pd(111). The calculation allows a configuration interaction treatm ent of a local region, while its interaction with the extended condensed ph ase is described via an embedding potential obtained from periodic density functional theory. Our work lays the foundation of a microscopic understand ing of photochemistry and spectroscopy on metal surfaces.