Self-diffusion and shear viscosity for the TIP4P/Ice water model.

Area of Science:

• Physical Chemistry
• Computational Fluid Dynamics
• Materials Science

Background:

• Accurate simulation of water properties is crucial, yet existing models often fail to predict both liquid and solid states accurately.
• The TIP4P/Ice model was specifically designed to simulate ice at its melting point, but its liquid-state dynamic properties remain under-explored.

Purpose of the Study:

• To calculate the transport coefficients of the TIP4P/Ice model for liquid water across a wide range of temperatures and pressures.
• To compare the dynamic properties of TIP4P/Ice with the established TIP4P/2005 model and experimental data.

Main Methods:

• Performing molecular dynamics simulations for the TIP4P/Ice model under varying thermodynamic conditions (245–350 K, 0–500 MPa).
• Calculating key transport coefficients, including self-diffusion and shear viscosity.
• Utilizing a corresponding states approach by rescaling temperature relative to the triple point.

Main Results:

• TIP4P/Ice exhibits lower self-diffusion and higher shear viscosity compared to TIP4P/2005 and experimental values.
• After temperature rescaling, TIP4P/Ice's transport coefficients align well with both TIP4P/2005 and experimental data.
• The study validates the use of TIP4P/Ice for liquid water simulations under specific conditions.

Conclusions:

• Despite its ice-centric development, TIP4P/Ice demonstrates reliable liquid water transport behavior when analyzed using a corresponding states framework.
• Findings suggest that existing extensive data for TIP4P/2005 can be leveraged for TIP4P/Ice by applying the described rescaling method.
• This research expands the utility of the TIP4P/Ice model and provides a method for predicting its dynamic properties in the liquid phase.