Decane under shear: A molecular dynamics study using reversible NVT‐SLLOD and NPT‐SLLOD algorithms

In a recent article [J. Chem. Phys. 102, 3376 (1995)] molecular dynamics (MD) was used to calculate the shear viscosity of liquid n‐decane using an intermolecular potential that reproduces the liquid–vapor coexistence as well as the critical temperature. Semi‐quantitative agreement with experiment was obtained. To further test the model, n‐decane is examined under shear using reversible nonequilibrium molecular dynamics (NEMD) in both the isothermal–isobaric (NPT) and the canonical (NVT) ensembles. The algorithm proposed herein, for studying a molecular system, is an atomic version of the so‐called SLLOD algorithm originally introduced by Edberg, Evans, and Morriss [J. Chem. Phys. 84, 6933 (1986)]. Results obtained by Daivis and Evans [J. Chem. Phys. 100, 541 (1994)] indicating the disappearance of a high shear‐rate (γ) thickening regime when the simulations are performed in the NPT ensemble are corroborated. The ‘‘plateau’’ region, where the viscosity is essentially independent of shear‐rate, γ is examined in detail in order to interpolate back to the Green–Kubo value.