Shear viscosities were computed for nine novel [guanidinium]^＋[Tf₂N]^－ ionic liquids by using non-equilibrium molecular dynamics (MD) (periodic perturbation method) method. The impact of simulation box sizes, steady-state velocity profiles and force field quality on calculated viscosity values are discussed. The simulations quantitatively capture the temperature and molecule-size dependence of viscosities. The calculated viscosities using extrapolation protocol are in good agreement with experimental data. The relative errors are within 12% at 353 K.

Key words: guanidinium-based ionic liquids, shear viscosity, non-equilibrium MD, periodic perturbation method