Ice formation and solvent nanoconfinement in protein crystals

Moreau, D.W.; Atakisi, H.; Thorne, R.E.

doi:10.1107/S2052252519001878

Figure 7
(a) Model of stacking-disordered ice (I_sd; adapted from Malkin et al., 2012

) showing O atoms connected by hydrogen bonds. Along the vertical direction [normal to the (001) planes in I_h and to the (111) planes in I_c], successive cubic ice planes are horizontally shifted, whereas successive hexagonal planes are mirror-reflected about a horizontal axis. On the left, C and H indicate pairs of planes that have cubic and hexagonal stacking, respectively. On the right, Φ_ch indicates the probability that a cubic stacking is followed by hexagonal stacking, and Φ_hc indicates the probability that a hexagonal stacking is followed by cubic stacking. (b, c) Cubic stacking fraction Φ_hc/(Φ_hc + Φ_ch) versus temperature for (b) apoferritin and (c) thaumatin crystals, determined from DIFFaX fits as in Figs. 6