The barrier model with random distribution of barrier energies is considered at nonzero particle concentrations. The statistical mechanics expressions for the jump diffusion coefficient that takes into account interparticle interactions are derived for dynamic and static disorder. For the former case the analytical expression for the barrier energy contribution is calculated, while for the latter case the limiting low and high temperature contributions are obtained. The derived expressions are tested by Monte Carlo simulations for uniform and exponential barrier energy distributions for one- and square, triangular and honeycomb two-dimensional lattices. (c) 2007 Elsevier B.V. All rights reserved.