High level ab initio calculations show that the self-induced dipole moment of a halide-water dimer deviates from the usually employed point dipole model, with a substantial nonlinear damping at separations corresponding to the first hydration shell. The total dipole moment is rather similar along the halide series, with the maximum value decreasing as anionic polarizability increases. A new implementation of the Thole damping method satisfactorily reproduces the dipole moment at all separations for the most probable configurations. (c) 2006 Elsevier B.V. All rights reserved.