Generalized Stillinger--David Potential

TL;DR

This paper introduces an improved Stillinger--David potential for water, incorporating new modeling approaches and corrections that better match quantum mechanical interaction energies and dipole behaviors.

Contribution

It presents a novel formulation of the water interaction potential, including a screening function and long-range corrections, enhancing accuracy over previous models.

Findings

Successfully reproduces quantum mechanical interaction energies

Provides a new approach to modeling charge-dipole screening

Estimates irreducible two-particle effects in water

Abstract

We present an improved version of the Stillinger--David polarization potential of the intermolecular interaction in water. A clear algorithm of construction of a function describing the oxygen-hydrogen interaction in water molecules is formulated. A new approach to the modeling of a function screening the charge-dipole interaction on small distances is developed. To describe the long-range asymptotics of the intermolecular potential, the bare Stillinger--David potential is supplemented by a term related to the interaction of dipole moments of oxygen ions. In addition, we introduce a term involving a deformation of the electron shells of oxygen ions to the polarization component. These corrections allow us to successfully reproduce all essential results of quantum mechanical calculations of the interaction energy for water molecules obtained by Clementi. Analyzing the behavior of the dipole moment of a water molecule as a function of the intermolecular distance, we obtain the estimate of irreducible two-particle effects in water.