Extended Data Figure 10: Square ice in nanocapillaries with different hydrophobicity.

a–d, Water droplets on surfaces with ε = 0.01 kcal mol⁻¹, 0.05 kcal mol⁻¹, 0.1 kcal mol⁻¹ and 0.2 kcal mol⁻¹, respectively. The changes in the relative strength of water–water and water–surface interactions result in different contact angles. For comparison, ε for the graphene–water interaction is 0.07 kcal mol⁻¹. e–h, Monolayer ice confined between surfaces with ε corresponding to a–d, respectively. In this case, the modelled walls are generic and do not have a discrete atomic structure, that is, their potential is uniform. h = 6.5 Å, the same as for the modelling of monolayer ice in the graphene nanocapillary in Extended Data Fig. 6.