Molecular-dynamics computer simulation of an aqueous NaCl solution: Structure

Publisher Website
Google Scholar
Abstract
A classical molecular-dynamics simulation of a 1.791 molal aqueous NaCl solution is performed using a flexible/polarizable five-site water model. Through an investigation of the ion-water pair-correlation functions and the relative orientation of the waters of hydration, we are able to study the solvation structure in this moderately concentrated salt solution. Under perturbations from the solvated ions, there appears a considerable reorganization of the water molecules. Some of the original intermolecular hydrogen bonding structure is broken down, as bonding with the neighboring cations and anions takes place. Also considered in this paper are the energetics of hydration, and the effect of ionic perturbations on properties such as the water intramolecular structure and vibrations, and the solution phase dielectric constant. An important conclusion from this work is that, in the NaCl solution studied here, perturbations on the water structure by the ions affect mainly intermolecular orientational properties. Although they may be large, these orientational effects are not sensitively detected by many experimental techniques, such as x-ray diffraction or vibrational spectroscopy.

This publication has 51 references indexed in Scilit: