Diffusion of interacting lattice gases on heterogeneous surfaces with simple topographies

Collective diffusion coefficients are studied for heterogeneous bivariate trap surfaces with different topographies. The topography is shown to affect strongly the coverage dependence and Arrhenius behavior of diffusion coefficients. The fluctuation and Kubo-Green methods are in strong disagreement, which is attributed to the failure of the former when the probe size is of the order of the applicable scale length for the lattice gas.