ELECTRON CORRELATION-EFFECTS IN ADSORPTION MODELS BASED ON THE ANDERSON HAMILTONIAN

The contribution of the electron correlation effects to the chemisorption energy and the excess charge on a one-level adsorbate is investigated. The investigation is carried out by means of analysis of the charge susceptibility and the set of characteristic functions describing the intensity of the electron-electron correlations, charge and electron spin fluctuations on an adatom. Three regions are considered within the parameter space: the strong-correlation region, the intermediate-valence region, and the region, where the Hartree-Fock approximation is valid.