An ab Initio, Infrared, and Raman Investigation of Phosphate Ion Hydration

The low-frequency infrared and Raman spectra of sodium and potassium phosphate solutions have been measured and discussed. The geometries, energies, and vibrational frequencies of various isomers of PO 4 3- (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.