Computer "Experiments" on Classical Fluids. II. Equilibrium Correlation Functions

Equilibrium correlation functions for a dense classical fluid are obtained by integrating the equation of motion of a system of 864 particles interacting through a Lennard-Jones potential. The behavior of the correlation function at large distance, and that of its Fourier transform at large wave number, are discussed in detail and shown to be related to the existence of a strong repulsion in the potential. A simple hard-sphere model is shown to reproduce very well the Fourier transform of those correlation functions at high density, the only parameter of the model being the diameter $a$ of the hard spheres.