Monte Carlo results were presented for the temperature dependence of the tracer diffusion coefficient in the square planar lattice gas with nearest-neighbor interactions at a concentration of 0.5. Below the order/disorder temperature the Arrhenius plot was linear. Above the order/disorder temperature the plot was curved towards lower activation energies. Results were also presented for the temperature dependence of the ratio of the tracer correlation factor to physical correlation factor - the Haven ratio. A remarkable discontinuity was found above the order/disorder temperature.

Computer Simulation Study of the Temperature Dependence of the Tracer Diffusivity and Haven Ratio in a Model of a Highly Defective Solid. G.E.Murch: Philosophical Magazine A, 1982, 45[6], 929-40