Monte Carlo computer simulation was used to investigate the tracer and physical correlation factors, and hence the Haven ratio in the honeycomb and square planar lattice gases with attractive and repulsive interactions at 50% occupation. The temperature dependence of the Haven ratio could be qualitatively understood in terms of effective changes in mechanism. The two particle correlation function was also consistent with these observations and also provided additional insight into the details of atomic transport.

Diffusion in the Lattice Gas I: the Haven Ratio. L.Zhang, G.E.Murch: Defect and Diffusion Forum, 1997, 141-142, 49-58