Structure and Transport Coefficients of Liquid Argon and Neon using Molecular Dynamics Simulation

Abstract

Molecular dynamics simulation was employed to deduce the dynamics property distribution function of Argon and Neon liquid. With the use of a Lennnard-Jones pair potential model, an inter-atomic interaction function was observed between pair of particles in a system of many particles, which indicates that the pair distribution function determines the structures of liquid Argon. This distribution effect regarding the liquid structure of Lennard-Jones potential was strongly affected such that its viscosity depends on density distribution of the model. The radial distribution function, g(r) agrees well with the experimental data used. Our results regarding Argon and Neon show that their signatures are quite different at each temperature, such that their corresponding viscosity is not consistent. Two sharps turning points are more prominent in Argon, one at temperature of 83.88 Kelvin (K) with viscosity of -0.548 Pascal second (Pa-s) and the other at temperature of 215.64 K with viscosity of -0.228 Pa-s.

In Argon and Neon liquid, temperature and density are inversely and directly proportional to diffusion coefficient, in that order. This characteristic suggests that the observed non linearity could result from the non uniform thermal expansion in liquid Argon and Neon, which are between the temperature range of 21.98 K and 239.52 K.