Nearest-neighbour distribution function for systems on interacting particles

One of the basic quantities characterising a system of interacting particles is the nearest-neighbour distribution function H(r). The authors give a general expression for H(r) for a distribution of D-dimensional spheres which interact with an arbitrary potential. Specific results for H(r) are obtained, for the first time, for D-dimensional hard spheres with D=1, 2 and 3. Their results for D=3 are shown to be in excellent agreement with Monte Carlo computer-simulation data for a wide range of densities. From H(r), one can determine other quantities of fundamental interest such as the mean nearest-neighbour distance and the random close-packing density.