A better resolution is offered by the examination of H-bond jump times, which also allows examining the molecular determinants of the hydration dynamics spatial heterogeneity. As previously shown, water reorientation occurs mainly through large angular jumps that occur during exchanges of H-bond partner. Since a water molecule needs to exchange H-bond acceptor to move away from an initial H-bond acceptor site on the DNA or RNA surface, the jump time (see Supporting Information) reports on the H-bond dynamics at a very well defined location, or "site". Maps of the jump times on the nucleic acids surface (see SI Fig. ) show very similar characteristics as that of reorientation times, confirming indirectly that the jump is indeed the main ingredient of water reorientation in the hydration shell.