Dielectric and Structural Study of Water with Various NaCl Concentrations via Molecular Dynamics

TL;DR

This study investigates how varying NaCl concentrations affect water's dielectric and structural properties using molecular dynamics simulations with different ion models.

Contribution

It introduces a comparative analysis of two ion models in molecular dynamics simulations of saline water across a range of concentrations.

Findings

Enhanced understanding of NaCl's effect on water structure and dielectric properties.

Comparison of ion models reveals differences in system behaviour.

Use of advanced water model improves property predictions.

Abstract

Specifically, we examine concentrations from [NaCl]=1m to [NaCl]=6m, where 6.1m represents the solubility threshold of NaCl in H2O. For the water model, we employ the flexible TIP4P/$\epsilon_{Flex}$ model, which offers an enhanced reproduction of various properties compared to other flexible models and non-polarisable rigid models. This includes improvements in the prediction of the infrared spectrum. For the ions, we utilise two distinct models: NaCl/Madrid and NaCl/$\epsilon$, allowing for a comparative analysis of their impact on the system's behaviour.