Simulation of Diatomic Homonuclear Liquids

Abstract

The molecular-dynamic method was used to simulate a fluid of 500 rigid diatomic homo-nuclear molecules interacting by a double Lennard-Jones potential. The equilibrium and time-dependent properties are calculated in the liquid phase. The computed pressure and the internal energy agree quantitatively to a few percent with experimental values for nitrogen. The reorientational and the velocity of the center-of-gravity self-correlation functions are also discussed. The memory-function formalism and the extended-diffusion models are used to interpret the reorientational self-correlation functions. The analysis reveals that these self-correlation functions have an exponential behavior for times larger than 5 \ifmmode\times\else\texttimes\fi{} 1${0}^{\ensuremath{-}13}$ sec. In this model, considering present computing precision, there is no observable hydrodynamic-type relaxation in the reorientational self-correlation functions.