A study of the ice-water interface using the TIP4P/2005 water model

Area of Science:

• Physical Chemistry
• Materials Science
• Computational Physics

Background:

• The ice-water interface is crucial for diverse natural phenomena and technological applications.
• Accurate quantification of interfacial properties, such as free energy, is essential for understanding phase transitions.
• Previous estimations of ice-water interfacial free energy have varied, necessitating further investigation.

Purpose of the Study:

• To determine the orientationally averaged interfacial free energy of ice in equilibrium with liquid water.
• To calculate the interfacial free energy for specific crystallographic planes of ice (basal, primary prismatic, secondary prismatic).
• To characterize the structural properties, including thickness and phase coexistence, of the ice-water interface.

Main Methods:

• Molecular simulations employing the TIP4P/2005 water model.
• Analysis of capillary fluctuation spectra to measure interfacial free energy, following Hoyt et al.'s methodology.
• Estimation of free energies for distinct crystallographic planes and characterization of interface structure.

Main Results:

• An orientationally averaged interfacial free energy of 27(2) mN m⁻¹ was obtained.
• Specific plane free energies were determined: 27(2) mN m⁻¹ (basal), 28(2) mN m⁻¹ (primary prismatic), and 28(2) mN m⁻¹ (secondary prismatic).
• The ice-water interface was found to be approximately 4-5 molecular diameters thick, with the basal plane exhibiting alternating cubic and hexagonal ice regions.

Conclusions:

• The calculated interfacial free energy aligns well with recent simulation-based estimates.
• The study provides detailed interfacial free energy values for different ice planes.
• Structural analysis reveals the interface's thickness and complex coexistence of ice phases at the basal plane.