Diffusion coefficient and shear viscosity of rigid water models.
Sami Tazi1, Alexandru Boţan, Mathieu Salanne
1CNRS and UPMC Université Paris-06, UMR 7195 PECSA, 75005 Paris, France.
Summary
We calculated the diffusion coefficient and viscosity for rigid water models, finding TIP4P/2005 best matches experimental data. SPC/E and Dang-Chang models showed discrepancies in diffusion and viscosity predictions.
Area of Science:
- Computational chemistry
- Molecular dynamics simulations
- Physical chemistry
Background:
- Accurate molecular models are crucial for simulating water properties.
- Existing rigid water models (SPC/E, TIP4P/2005, Dang-Chang) vary in their predictive accuracy.
- Understanding diffusion and viscosity is key to characterizing fluid behavior.
Purpose of the Study:
- To determine the size-independent diffusion coefficient and viscosity for SPC/E, TIP4P/2005, and Dang-Chang water models.
- To compare simulation results with experimental data and Green-Kubo predictions.
- To evaluate the accuracy of different rigid water models.
Main Methods:
- Utilizing system-size dependence analysis to extrapolate diffusion coefficients to the thermodynamic limit.
- Estimating viscosity from diffusion coefficient calculations.
- Comparing simulation-derived properties with experimental values and established theoretical results.
Main Results:
- TIP4P/2005 demonstrated superior agreement with experimental diffusion and viscosity data.
- SPC/E and Dang-Chang models overestimated diffusion coefficients.
- SPC/E and Dang-Chang models underestimated viscosity compared to experimental values.
Conclusions:
- TIP4P/2005 is recommended for accurate simulations of water diffusion and viscosity.
- SPC/E and Dang-Chang models may require adjustments for precise dynamic property predictions.
- System-size extrapolation is a reliable method for obtaining accurate diffusion coefficients.
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