1. Newns-Anderson model for Chemisorption
Bo Hellsing
Department of Physics, Göteborg University, Göteborg, SWEDEN
Atom
Metal

2. Newns-Anderson model Hamiltonian
Vak
| a >
| k >

3. and the adsorbate-substrate binding energy - chemisorption energy.
We will apply the Hartree-Fock approximation (mean filed approximation).
The adsorbate Green's function is obtained which can be used to calculate e.g.
electron charge transfer between the adsorbate and the substrate
and the adsorbate-substrate binding energy - chemisorption energy.
Crusial quantities are the adsorbate-substrate
interaction Vak and the coulomb interaction on the adsorbate U.
The retarded Green's function has the elements:

4. We now derive the equation of motion for the Green's functions.
We start by taking the time derivative:

5. Heisenberg:
We thus get

6. Hand-in problem I:
We thus get