Modeling water using multipole response tensors fitted to the monomer geometry

Area of Science:

• Computational Chemistry
• Molecular Modeling
• Physical Chemistry

Background:

• Accurate modeling of molecular interactions is crucial for understanding chemical systems.
• Water's unique properties necessitate precise computational descriptions of its electronic structure and interactions.

Purpose of the Study:

• To develop a robust computational model for predicting the electrostatic, induction, and dispersion energy components of flexible water molecules.
• To achieve high accuracy comparable to coupled-cluster methods (CCSD(T)) for molecular interactions.

Main Methods:

• Gaussian process regression was used to fit electronic multipole moment and polarizability tensors to internal coordinates.
• A dispersion potential based on multipole polarizabilities was employed.
• Short-range potential energy was corrected using Gaussian approximation potentials.
• Molecular dynamics simulations were performed to calculate the radial distribution function and self-diffusion coefficient.

Main Results:

• The developed model accurately reproduces electrostatic, induction, and dispersion energies.
• The model parameters were optimized against symmetry-adapted perturbation theory and CCSD(T) calculations.
• Molecular dynamics simulations yielded results for the radial distribution function and self-diffusion coefficient that align well with experimental data.

Conclusions:

• The proposed computational model provides an accurate and efficient method for simulating flexible water molecules.
• The model's ability to reproduce experimental properties highlights its potential for various chemical and physical applications.