Lennard Jones Viscosities in Wide Ranges of Temperature and Density: Fast Calculations Using a Steady-State Periodic Perturbation Method.

V.R. VASQUEZ; E.A. MACEDO; M.S. ZABALOY

International Journal of Thermophysics

Springer Netherlands

Año: 2004 vol. 25 p. 1799 - 1818

0195-928X

A method for fast calculation of viscosity from molecular dynamics simulation is revisited. The method consists of using a steady-state periodic perturbation. A methodology to choose the amplitude of the external perturbation, which is one of the major practical issues in the original technique of Gosling et al. [Mol. Phys. 26: 1475 (1973)] is proposed. The amplitude of the perturbation required for fast calculations and the viscosity values for wide ranges of temperature and density of the Lennard-Jones (LJ) model fluid are reported. The viscosity results are in agreement with recent LJ viscosity calculations. Additionally, the simulations demonstrate that the proposed approach is suitable to efficiently generate viscosity data of good quality. KEY WORDS: Lennard-Jones; molecular dynamics; periodic perturbation methods; transport properties; viscosity.