Water modeled as an intermediate element between carbon and silicon.

Area of Science:

• Computational Physics and Chemistry
• Materials Science
• Chemical Physics

Background:

• Water exhibits unique physical properties, including a temperature of maximum density and tetrahedral crystal/amorphous phases, shared with silicon and carbon due to tetrahedral coordination.
• Existing water models often rely on computationally expensive long-ranged forces (e.g., electrostatics) to capture short-ranged hydrogen-bonded structures.

Purpose of the Study:

• To develop a novel coarse-grained water model (mW) inspired by the similarities between water, silicon, and carbon.
• To accurately reproduce water's thermodynamic and structural properties, including anomalies and phase transitions, using only short-range interactions.

Main Methods:

• Developed the mW model, a coarse-grained representation of water, incorporating an angular-dependent term to enforce tetrahedral configurations.
• This model utilizes exclusively short-range interactions, departing from traditional long-range force approaches in water modeling.

Main Results:

• The mW model accurately reproduces the energetics, density, and structure of liquid water, including its anomalies and phase transitions.
• Achieves comparable or superior accuracy to popular atomistic models at less than 1% of the computational cost.
• Demonstrates that molecular connectivity, rather than interaction type, dictates water's structural and thermodynamic behavior.

Conclusions:

• The mW model provides a computationally efficient and accurate representation of water, validating the importance of tetrahedral connectivity.
• Its speedup makes it ideal for simulating slow dynamic processes, such as deeply supercooled water behavior, ice nucleation, and wetting-drying phenomena.
• Presents a realistic water model for large-scale coarse-grained simulations of biomolecules and complex materials.