Polarizable TIP7P Water Model with Perturbation Charges Evaluated from ABEEM

Area of Science:

• Computational Chemistry
• Molecular Dynamics
• Physical Chemistry

Background:

• Accurate molecular models are crucial for simulating water properties.
• Existing rigid water models like TIP7P have limitations in capturing polarizability effects.
• The atom-bond electronegativity equalization method (ABEEM) offers a framework for developing polarizable models.

Purpose of the Study:

• To develop and validate a polarizable water model based on the TIP7P structure using the ABEEM method.
• To investigate the performance of direct polarization in molecular simulations.
• To improve the accuracy of simulating thermodynamic and transport properties of water.

Main Methods:

• A novel polarizable seven-site water model (TIP7P-ABEEM) was developed using direct polarization.
• The model incorporates a Slater-type damping function for short-range electrostatics and Ewald summation for long-range interactions.
• Parameterization involved fitting to ab initio calculations of water clusters and experimental data for liquid water.

Main Results:

• The TIP7P-ABEEM model demonstrates improved accuracy for vaporization enthalpy, isothermal compressibility, and shear viscosity compared to the TIP7P model.
• The model shows better performance at the melting point of ice.
• Direct polarization exhibits a low time complexity of O(N), enhancing computational efficiency.

Conclusions:

• The proposed polarizable water model with direct polarization and ABEEM provides a more accurate representation of liquid water properties.
• The direct polarization method is computationally efficient and suitable for ABEEM.
• This model represents a significant advancement for molecular simulations of water.