Chemisorption theory for metallic surfaces: Electron localization and the description of surface interactions

A theory for describing molecule-solid surface interactions using correlated configuration-interaction (CI) wave functions for the surface region is described. Starting with a delocalized self-consistent-field wave function for the lattice, approximated as a cluster of atoms, a local surface region is defined by a unitary, localization transformation of the single-particle orbitals of the lattice wave function based on electron exchange maximization with the surface sites of interest. CI calculations on the resulting N-electron subspace plus adsorbate permit an accurate description of bonding at the surface. Ab initio computational techniques for treating the many-electron problem and large clusters of metal atoms are described.