Modelling the effect of the electrode potential on the metal-adsorbate surface states: relevant states in the charge transfer mechanism of SERS.

Quantum mechanical calculations of the ground and excited electronic states of several [Ag(n)-pyridine](q) complexes yield a linear dependence of the energies of the surface states, especially the metal-to-molecule charge transfer states, on q(eff) = q/n. This is the first theoretical approach to modelling the effect of the electrode potential on SERS.