An ab initio molecular dynamics study of diffusion, orientational relaxation and hydrogen bond dynamics in acetone-water mixtures

► Water-acetone mixtures are studied through ab initio molecular dynamics and time series analysis. ► Time scales of diffusion and orientational relaxation exhibit nonlinear dependence on concentration. ► The dynamics of water-water and water-acetone hydrogen bonds and free OD groups are investigated. ► Vibrational spectral diffusion is also studied for OD groups in different hydrogen bonding environments. ► Results of spectral diffusion are correlated with the dynamics of hydrogen bonds and also of dangling OD groups.