Wurtzite crystal structure


The wurtzite crystal structure, named after the mineral wurtzite, is a crystal structure for various binary compounds. It is an example of a hexagonal crystal system. The chemical prototype is conventionally given as ZnS.
The wurtzite crystal structure is referred to by the Strukturbericht designation B4 and the Pearson symbol hP4. The corresponding space group is No. 186 or P63mc. The Hermann-Mauguin symbols in P63mc can be read as follows:
Among the compounds that can take the wurtzite structure are wurtzite itself, AgI, ZnO, CdS, CdSe, α-SiC, GaN, AlN, w-BN and other semiconductors. In most of these compounds, wurtzite is not the favored form of the bulk crystal, but the structure can be favored in some nanocrystal forms of the material.
In materials with more than one crystal structure, the prefix "w-" is sometimes added to the empirical formula to denote the wurtzite crystal structure, as in w-BN.
Each of the two individual atom types forms a sublattice which is HCP-type. When viewed altogether, the atomic positions are the same as in lonsdaleite. Each atom is tetrahedrally coordinated.
The wurtzite structure is non-centrosymmetric. Due to this, wurtzite crystals can have properties such as piezoelectricity and pyroelectricity, which centrosymmetric crystals lack.