The shear viscosities of common water models by non-equilibrium molecular dynamics simulations

Abstract

We have performed non-equilibrium molecular dynamics simulations to simulate the shear viscosity of five commonly used water models, SPC, SPC/E, TIP3P, TIP4P and TIP5P, using the periodic perturbation method. By comparing the computed viscosities of the water models, we find that the viscosities of SPC/E and TIP5P are in better agreement with the experimental value than the others. Furthermore, we have systematically investigated the effects of system size, acceleration amplitude, electrostatic treatment and cut-off length on the viscosities of the SPC/E and TIP5P models. Finally, by simulating the viscosity of water as a function of temperature, our work suggests that the SPC/E and TIP5P models reasonably reproduce the water viscosity vs. temperature experimental profile from 283 to 373 K at 1 bar, although SPC/E gives a better viscosity at high temperatures and TIP5P reproduces closer viscosity values at low temperatures.

Keywords:

• shear viscosity
• water models
• non-equilibrium molecular dynamics simulation

Acknowledgements

We thank the Arizona State University Fulton High-Performance Computing Initiative (HPCI) for providing the computational resources. We are also grateful to the financial support from the National Science Foundation 0922277.