Low-coverage K adsorption on Mg(0 0 0 1) surface

First principles methods are applied to study the energetics of p(2 × 2) and (3×3)R30 configurations of K atoms adsorbed in a variety of sites on the Mg(0 0 0 1) surface. It is found that for coverages Θ⩽1/3 monolayer the on-surface hollow sites are most stable and the adsorption binding energy increases with the coverage. The results are compared with the previous calculation by Neugebauer and Scheffler for alkali metal adsorption on the Al(1 1 1) surface.