Monte Carlo computer simulations were made of a tracer particle that hopped through a lattice in which the sites could be empty, or be occupied by 1 or 2 background particles. The results for the diffusion coefficient were compared with those of a mean-field theory that was based upon a random-walk approach. Blocking effects which were due to dynamic background particles were obtained exactly, and correlation effects which were due to many-particle interactions were analyzed qualitatively. It was suggested that this type of double occupancy model could be applied to the study of ionic conduction in glasses.

L.F.Perondi, R.J.Elliott, R.A.Barrio, K.Kaski: Physical Review B, 1994, 50[14], 9868-74