Structure and vibrational spectra of cluster ions over rubidium iodide by computational chemistry

The properties of Rb₂I⁺, RbI₂^-, Rb₃I₂⁺ and Rb₂I₃^- ions were studied using two quantum chemical methods, DFT and Møller-Plesset perturbation theory of the 2^nd order. The effective core potential with Def2-QZVP basis set for rubidium atom and SDB-aug-cc-pVTZ basis set for iodine atom were used. According to the results, the equilibrium geometric structure of the triatomic ions was found to be linear of D_∞h symmetry. For the pentaatomic ions, the three isomeric forms were found: the linear (D_∞h), the kite-shaped (C_2v), and the bipyramidal (D_3h), both for the positive and negative ions. For all species, the equilibrium geometric parameters and vibrational spectra have been determined.