Crystal structure
![The (3-D) crystal structure of H2O ice Ih (c) consists of bases of H2O ice molecules (b) located on lattice points within the (2-D) hexagonal space lattice (a). The values for the H–O–H angle and O–H distance have come from Physics of Ice[1] with uncertainties of ±1.5° and ±0.005 Å, respectively. The black box in (c) is the unit cell defined by Bernal and Fowler[2]](/uploads/202412/22/Ice_Ih_Crystal_Lattice0249.png)
In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms, ions or molecules in a crystalline liquid or solid. It describes a highly ordered structure, occurring due to the intrinsic nature of its constituents to form symmetric patterns.