2ND-HARMONIC GENERATION AND THE MICROSCOPIC STRUCTURE OF THE METAL ELECTROLYTE INTERFACE

A model for second harmonic generation at the metal-solution interface is presented and treated by electron density functional calculations. The coefficient a, characterizing the non-linear optical response perpendicular to the surface, is calculated both for bare metal electrodes and for metals covered with an overlayer of a different metal. The analysis for bare metals is performed with a lattice of pseudopotentials, thus introducing crystal structure into the model.