Modeling diffusion on heterogeneous lattices: honeycomb lattice

We investigate diffusion of particles adsorbed on a heterogeneous honeycomb lattice with two kinds of non-equivalent sites. General analytical expressions for the chemical and jump diffusion coefficients have been derived in the case of strong inhomogeneity. It is shown that the character of the particle migration depends crucially on the relative jump frequencies of particles occupying deep and shallow sites. In the case of widely differing jump frequencies, particles perform pairs of strongly correlated jumps. We have calculated coverage dependencies of the diffusion coefficients and some thermodynamic quantities for attractive and repulsive lateral pairwise interactions and compared them with the results of the kinetic Monte Carlo simulations of the particle diffusion. Almost perfect agreement between the respective results has been found.