wurtzitetype

Wurtzite-type refers to a class of crystal structures characterized by a hexagonal close-packed arrangement of anions with cations occupying half of the tetrahedral interstices. The prototype is the wurtzite structure, as exemplified by zinc sulfide (ZnS) in its hexagonal form. This structure is commonly described by the hexagonal space group P63mc and features ABAB stacking of the close-packed anion layers, yielding hexagonal symmetry. In the wurtzite arrangement, each cation is tetrahedrally coordinated to four anions and each anion to four cations, giving a fourfold coordination environment throughout the lattice.

Many compounds crystallize in a wurtzite-type structure or closely related derivatives, particularly II–VI and III–V semiconductors such as GaN, AlN, ZnO and BeO. Some materials can also exist in zinc blende (cubic) form, which is the sister polytype with ABC stacking and the space group F-43m; crystals may transition between wurtzite-type and zinc blende forms under changes in temperature, pressure, or composition.

Properties associated with wurtzite-type materials include wide band gaps for nitrides and oxides, strong anisotropy in optical and electronic behavior, and, in several compositions (notably GaN and AlN), notable piezoelectric effects. The term is used in crystallography and materials science to classify compounds whose ideal structure aligns with this hexagonal framework, even when real crystals exhibit distortions or mixed polytypes.