Correlated studies of electric properties of ionic molecules: alkali and alkaline-earth hydrides, halides and chalcogenides

Electric polarizabilities, dipole and quadrupole moments of the molecules LiH, LiF, LiCl, NaH, NaF, NaCl, BeO, BeS, MgO, MgS, BeH, BeF, BeCl, MgH, MgF, MgCl, LiO, LiS, NaO and NaS are computed in a uniform basis at the correlated level of theory. The results are rationalized in terms of the properties of ion pairs, and the stability of the isolated anions: the hydrides, oxides and sulphides show large and positive correlation corrections to the polarizability in CASSCF, and erratic convergence of the MBPT series. The open-shell alkaline-earth hydrides and halides in the series all exhibit negative polarizability anisotropy.