Theory of the surface dipole on nontransition metals

The authors report calculations of the surface dipole contribution to the electron work function for 19 nontransition metals, using the experimental cohesive energies and work functions of the solids. For the alkali and alkaline earth metals, which have low electron density, the helium model of Lang and Kohn (1971) is found to apply well. In the polyvalent metals of higher electron density, the work function is stabilized very efficiently around 4.1+or-0.4 eV by the surface dipole in spite of considerable variation in the internal chemical potential.