An ab Initio and Raman Investigation of Sulfate Ion Hydration

The Raman spectra of ammonium sulfate solution are measured. The geometries, energies, and vibrational frequencies of various isomers of SO 4 2- (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.