The sulfur-ammonia (S-NH3) cycle uses the entire solar radiation spectrum to split water. It uses the UV radiation to promote the photolytic oxidation of ammonium sulfite to produce hydrogen and ammonium sulfate. Here, Raman and inelastic neutron scattering spectra of (NH4)(2)SO3 center dot H2O at 20 K are discussed, supported by density functional theory (DFT) calculations. The feasibility of photolytic oxidation of this monohydrate to produce hydrogen at room temperature was also demonstrated. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.