Alkali metal adsorption on graphite: Calculation of a work function variation in the Anderson–Newns–Muscat model

Within the scope of the Anderson–Newns model of adsorption the Na, K, and Cs submonolayer films on graphite are considered. The adatoms dipole–dipole repulsion is taken into account with the use of the Muscat approach. The calculated work function variations are in a reasonable agreement with the experimental data. We have found that the charges of K, Na, and Cs adatoms are Z0 = 0.22, 0.38, and 0.41 for the zero coverage limit and ZML = 0.09, 0.15, and 0.16 for the monolayer coverage correspondingly. The crude estimations of the single adatom binding energies got Eb = 0.76, 0.67, and 0.37 eV for Na, K, and Cs accordingly.