Classical and ab initio quantum mechanical/molecular mechanical (QM/MM) molecular dynamics simulations have been performed to investigate structural and dynamical properties of the hydrated Ru3+. The average Ru3+-O distance evaluating in the QM/MM simulation is 2.10 angstrom for the first hydration shell, and the coordination numbers are 6/10 for first/second hydration shell. Several structural parameters such as angular distribution functions, and tilt- and theta-angle distributions were determined to characterize the hydration structure of Ru3+. Ligand exchange processes between the second hydration shell and the bulk occur with a mean residence time of 6.5 ps. (c) 2007 Elsevier B.V. All rights reserved.