DIFFUSIVITY AND MOBILITY OF LATTICE GASES IN LATTICES WITH RANDOMLY BLOCKED SITES

Lattice gases on simple-cubic lattices with randomly blocked sites are studied by numerical simulations. The behaviour of the single-particle diffusion coefficient is well described by a linear relation for small and moderate defect concentrations. It is verified that the collective diffusion coefficient coincides with the single-particle diffusion coefficient, for various defect concentrations and for the model of non-interacting lattice gases. The validity of the Nernst-Einstein relation between the collective diffusion coefficient and the mobility is also verified. The tracer diffusion coefficient and the correlation effect has been studied as a function of the concentration of the blocked sites. Also the dependence of the variance of the single-particle diffusion coefficient on lattice size, particle number, and length of time intervals has been explored. © 1990 Taylor & Francis Group, LLC.