THE CLUSTER MODEL CONFIGURATION-INTERACTION APPROACH TO THE STUDY OF CHEMISORPTION ON METAL AND SEMICONDUCTOR SURFACES

The configuration interaction (CI) approach to the study of chemisorption on metal and semiconductor surfaces is described through the use of some selected examples as atop and four-fold H on Cu(100), four-fold interaction of O on Cu(100) and Al on Si(111) at three different sites. Electronic correlation effects on structural parameters and on the description of the surface chemical bond are analyzed by comparing Hartree-Fock and CI wavefunctions. The analysis of dipole moment curves and of the electrical field effects induced by a uniform external field permits the importance of electronic correlation to be quantified in the description of the chemical interaction between an adsorbate and a surface.