The calculation of the chemisorption energy using the new diagram technique for the Anderson model

Using the perturbation expansion in the rebonding interaction near the surf ace molecule limit, the new diagram technique for the calculation of the ch emisorption energy in the Anderson model is proposed. The new expression fo r the chemisorption energy in the ring diagram approximation is presented. The approximate expression for the contribution of the non- ring diagrams i s suggested. The chemisorption energies are calculated and compared with th e available exact results and others in the literature. A simple explanatio n of observable trends in hydrogen chemisorption energies along the transit ion metal series is given based on the rebonding surface molecule picture.