Computer "Experiments" on Classical Fluids. III. Time-Dependent Self-Correlation Functions

Molecular dynamics experiments made on a system of 864 particles interacting through a Lennard-Jones potential for various high-density states are used to study the self-correlation in classical fluids. The self-diffusion constant is computed and interpreted in terms of a hardsphere model. The memory-function formalism is used to give a simple phenomenological fit for the computed velocity autocorrelation function and for the self-intermediate-scattering function. A detailed comparison is made with the various existing theories for the latter quantity.