An ab initio study of the effect of hydration on the vibrational spectrum of hydrogen selenate ion

Abstract

• Various isomers of HSeO 4 - (H 2 O) n , n = 0 – 6 are calculated up to MP2/6–31 + G*. • The geometry and vibrational frequencies are studied as a function of cluster size. • Differences between HSeO 4 - in an ionic liquid and water are explained. • A large temperature dependence of the Se-O(H) stretching and SeOH deformation frequencies is predicted. The geometries, energies, and vibrational frequencies of various isomers of HSeO 4 - (H 2 O) n , n = 0 – 6 are calculated at various levels up to MP2/6–31+G*. These properties are studied as a function of increasing cluster size. The experimental and theoretical vibrational spectra are compared. The calculations help to predict the full-widths at half-height and a strong temperature and solvent dependence of the Se-O(H) stretching and SeOH bending vibration.