Figure 9.

Effect of crowding on water structure and dynamics. For water molecules between two proteins (a) and four proteins (b), the number of H bonds is practically unchanged with the degree of confinement (c), while the H-bond dynamics exhibit a sharp transition at a distance which changes markedly with the confining geometry (d) (Reprinted with permission from ref (159). Copyright 2014 American Chemical Society.). There are alternate definitions for the HB lifetime than the one employed here, see, e.g., ref (58).