On the calculation by molecular dynamics of the shear viscosity of a simple fluid

An account is given of a steady-state molecular dynamics method for the calculation of the shear viscosity of a dense fluid. The method is applied to the case of a system described by a Lennard-Jones potential with parameters appropriate to argon. Satisfactory agreement with experimental data is found over a range of temperature and density for which the viscosity varies by a factor of approximately 8. The results are interpreted in terms of a modified hard-sphere model and it is shown that the Lennard-Jones fluid obeys a Stokes-type relation in which the effective molecular diameter is close to that deduced from equilibrium structural properties.