  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.
