Concentrated aqueous MgCl2 solutions. A computer simulation study of the solution structure and excess electron localisation

Abstract

Molecular Dynamics simulations of aqueous solutions of magnesium chloride were performed. The concentration of the solutions ranged from 0.2 to 4.9 M. The structures of hydration shells of the ions and the topological properties of the ionic structures were analysed using RDFs, Voronoi tessellations, coordination numbers, etc. The regions of crystalline order were found in concentrated MgCl2 solutions. Cation-centered clusters were selected to study the electron localisation. Quantum calculations were performed on the DFT level using 6-31++G** basis set. The absorption spectra of the excess electron in MgCl2 solutions were calculated by two different methods: histograms of the LUMO-HOMO energies and the excited states energies obtained from the time-dependent DFT.