Ice Polymorphs and Amorphous Ices: Its Structural Diversity and Hydrogen Bonds

Abstract

In this article, recent studies regarding structures of ice polymorphs and amorphous ices are briefly reviewed from the viewpoint of why ice polymorphs and amorphous ices have remarkable structural diversity. Characteristic structure in ice would be tetrahedral structural unit and inter- or intra-penetrating structure of hydrogen bonding network. The tetrahedrality and inter-/intra- penetrating structure in ice crystals could also characterize the structure of liquid water or amorphous ices. The concept of hydrogen-bond symmetrization, structure variation owing to plastic and super-ionic ices, and stacking structures hidden in ice polymorphs are also briefly discussed.