POLARIZABILITIES, ATOMS-IN-MOLECULES POLARIZABILITIES AND BONDING IN (CN)(-), (SCN)(-), (OCN)(-) AND (CLO)(-)

The gas-phase structures and dipole polarizabilities of cyanide, cyana te, thiocyanate and hypochlorite anions have been computed at various levels of theory up to MP4 (SDTQ). Electron correlation typically acco unts for some 17 of the total polarizability. Second-order Moller-Ples set corrections appear to dominate the correlation contribution to the polarizability. An atoms-in-molecules decomposition of the polarizabi lity tensors provides insight into the atomic origin of the polarizabi lity contributions, shows some transferability for the cyano nitrogen atoms, and may find application in the construction of anisotropic int ermolecular dispersion potentials. The bonding in these anions is disc ussed also in the framework of a bond critical point analysis of the e lectron density rho, the del(2) rho distribution, and bond dissociatio n energies.