A first principles simulation study of vibrational spectral diffusion in aqueous NaBr solutions: Dynamics of water in ion hydration shells

► Ab initio simulations are performed for water containing bromide ions of varying concentration. ► Frequency-structure correlations of water in Br− hydration shells are investigated. ► Dynamics of hydrogen bonds, frequency fluctuations and diffusion of water are looked at. ► Spectral hole dynamics calculations are performed for stretch modes of water in hydration shells. ► Links between the dynamics of hydrogen bonds and other modes with spectral diffusion are discussed.