HOPPING AND STATIC CORRELATIONS OF HIGHER ORDER IN A LATTICE GAS

Abstract
In interacting lattice gases at intermediate concentrations the hopping rate is determined by the static correlations of relatively high order among the neighbours of the diffusing particle. For a square lattice with nearest-neighbour exclusion the relevant correlation functions are studied by Monte Carlo simulation and analytically by an extended Bethe-Peierls cluster approximation. The results of both methods are in good agreement with each other and allow to test the accuracy of approximation schemes for higher-order correlation functions such as Kirkwood's superposition approximation and the Gaussian factorization.