EXPLICIT EQUATION FOR THE RADIAL-DISTRIBUTION FUNCTION OF A DENSE LENNARD-JONES FLUID

An equation is given for the radial distribution function (hereafter the rdf) of a dense Lennard-Jones fluid. The equation explicitly expresses the rdf as a continuous function of interparticle distance, temperature, and density. The parameters in the equation were obtained by fitting a three-variable function to molecular dynamics data on the rdf of a Lennard-Jones fluid. For the range of state variables of 0.50 ≲ T* < 5.0 and 0.35 ≲ ρ* ≲ 1.10 the equation provides rdf's with an average root-mean-squared deviation of 0.034. The error is about half this value in the low density-high temperature regions studied, and it is about double this value in the high density-low temperature regime. The equation predicts the internal energy and the pressure of a Lennard-Jones fluid with an uncertainty that is comparable to that obtained directly from molecular dynamics results. © 1979 American Chemical Society.