CHEMISORPTION AT FINITE COVERAGES - THE COHERENT-POTENTIAL APPROXIMATION VS THE EQUATION-OF-MOTION FOR GREENS-FUNCTIONS METHOD

The electronic structure, chemisorption energy and adatom charge of th e chemisorbed overlayer on a metal surface are studied within the mode l described by the Newns Hamiltonian generalized to finite coverages. It is shown that the method of equation of motion for appropriate Gree n's functions together with some decouplings of the higher-order Green 's functions can be used in calculations of the overlayer's electronic properties as an efficient and alternative way to the coherent potent ial approximation method.