DIFFUSION-COEFFICIENT FOR INTERACTING LATTICE GASES

Diffusion in an interacting adsorbate is analyzed with the use of a master equation for the lattice-gas model. The coefficient of chemical diffusion for the diluted, interacting adsorbate is calculated using concepts of diffusion theory in a disordered medium in which the random potential is related to the local field that affects each particle due to the particle interactions. We use the random-local-field method to evaluate the distribution of local fields in the equilibrium state. Results obtained for the simplest, interacting lattice gas are successfully compared with Monte Carlo simulations. © 1994 The American Physical Society.