Short-range contributions to the polarization of cations

Charge-overlap cluster calculations [Wheatley, R, J. Chem. Phys. Lett. 1998 , 294, 487], in which the electronic structure of a central ion is modified self-consistently by the frozen densities of its neighbors, are used to mo del induced dipoles in the condensed-phase alkali metal halides. Two distin ct effects of overlap are identified: exchange-repulsion and Coulomb correc tions. For anions, both substantially reduce the dipole from its asymptotic value; for cations, the two short-range effects are opposed, producing sma ll net short-range corrections of different sign for different alkali metal cations.