Classical molecular dynamics simulations with a polarizable force field indicate two major structural motifs for the aqueous bulk solvation of OH-: a four- and a five-coordinated solvent hydrogen bond donor to OHV in addition to a weak solvent hydrogen bond acceptor by OH-. A two-step mechanism for the reorientation of OH- in water is proposed: first, the reorientation of OH- is initiated by the coupled translation with the water molecules in its first solvation shell; second, the OH- relaxes to the minimum energy configuration. The first step is the rate-limiting one for this mechanism. (C) 2009 Elsevier B.V. All rights reserved.