Influence of polarization and many body quantum effects on the solvation shell of Al(III) in dilute aqueous solution--extended ab initio QM/MM MD simulations.

Structural properties of the hydrated Al(III) ion have been investigated by ab initio quantum mechanical/ molecular mechanical (QM/MM) molecular dynamics (MD) simulations at double zeta HF quantum mechanical level including only the first and first plus second hydration shell into the QM region. The coordination number in the first shell was found to be 6.0 in both cases, but the inclusion of the second shell into the QM region causes significant changes in the properties of the hydrate. Several structural parameters such as angular distribution functions, radial distribution functions and tilt- and theta-angle distributions were used to fully characterise the hydration structure of Al(III).