Surface diffusion in a system of particles, adsorbed on a lattice with 2 non-equivalent sites (whose number in the unit cell and adsorption energy were different) was investigated. When the adsorption energies were comparable, the ad-particle diffusion proceeded via uncorrelated ad-particle jumps. In the opposite case, ad-particle migration proceeded via pairs of consecutive jumps. The contribution of these jump sequences to surface diffusion depended upon the ad-particle surface coverage and the relationship between the adsorption energies.

Surface Diffusion of Particles Adsorbed on a Lattice with Two Non-Equivalent Sites. A.A.Tarasenko, L.Jastrabík: Surface Science, 2002, 507-510, 108-13