Shear-Rate Dependence of the Viscosity of Simple Fluids by Nonequilibrium Molecular Dynamics

New molecular-dynamics data are reported for the shear viscosity of a Lennard-Jones fluid as a function of the shear rate $\dot{\epsilon }$, $\eta \left(\dot{\epsilon }\right)$ is deduced from the transient behavior of the system suddenly subjected to a planar Couette flow. $\eta \left(\dot{\epsilon }\right)$ is found insensitive to $\dot{\epsilon }$ for $\dot{\epsilon }<1\mathrm{}$ (in reduced units) and in complete agreement with the Green-Kubo value $\eta \mathrm{}\left(0\right)\mathrm{}$. At higher $\dot{\epsilon }$, the expression $\eta \left(\dot{\epsilon }\right)\approx 1.29-0.013{\dot{\epsilon }}^2$ reproduces our data fairly well.