An ab initio molecular dynamics study of supercritical aqueous ionic solutions: Hydrogen bonding, rotational dynamics and vibrational spectral diffusion

► Supercritical aqueous solutions are investigated through ab initio molecular dynamics. ► The ion-water structure and frequency-structure correlations are investigated. ► Stretch frequency of water in anion hydration shell is found to be lower than bulk value. ► Orientational relaxation, dynamics of hydrogen bonds and free OD groups are investigated. ► Dynamics of vibrational spectral diffusion is studied for hydration shell and bulk water.