A new classical interaction potential for water simulations is presented. Water is modeled as a fully dissociable set of atoms with a point dipole, determined self-consistently, on every oxygen atom. The oxygen polarizability is not fixed but depends on the geometry of the system. We show that, in spite of the limited number of free parameters, the model reproduces the geometrical and vibrational properties of microclusters in a satisfactory way. (C) 2003 Elsevier B.V. All rights reserved.