A first principles molecular dynamics simulation of the hydrated magnesiumion

First principles molecular dynamics has been used to investigate the solvat ion of Mg2+ in water. In agreement with experiment, we find that the first solvation shell around Mg2+. contains six water molecules in an octahedral arrangement. The electronic structure of first solvation shell water molecu les has been examined with a localized orbital analysis. We find that water molecules tend to asymmetrically coordinate Mg2+ through one of the oxygen lone pair orbitals and that the first solvation shell dipole moments incre ase by 0.2 Debye relative to pure liquid water. (C) 2001 Published by Elsev ier Science B.V.