Diffusion and viscosity equations of state for a Lennard-Jones fluid obtained from molecular dynamics simulations

Equilibrium molecular dynamics simulations were performed for a Lennard-Jones fluid at 171 conditions spanning the range 0 less than or equal to rho(+) less than or equal to 1.0 and 0.8 less than or equal to T+ less than or equal to 4.0. The Einstein or mean-squared-displacement (MSD) formula was used to compute the self-diffusion coefficient and a recently suggested, modified MSD equation was used to compute the shear viscosity at each condition. Analytical equations for the self-diffusion and viscosity coefficients were then fitted to the simulated data as polynomial functions of rho(+) and T+. The resultant smoothing equations correlate the simulated data quite well and agree with argon experimental data within the uncertainty of the data.