Tetragonal crystal system

In crystallography, the tetragonal crystal system is one of the 7 crystal systems.

Tetragonal crystal lattices result from stretching a cubic lattice along one of its lattice vectors, so that the cube becomes a rectangular prism with a square base (a by a) and height (c, which is different from a).

The body-centered tetragonal lattice is equivalent to the primitive tetragonal lattice with a smaller unit cell, while the face-centered tetragonal lattice is equivalent to the body-centered tetragonal lattice with a smaller unit cell.

[1] The point groups that fall under this crystal system are listed below, followed by their representations in international notation, Schoenflies notation, orbifold notation, Coxeter notation and mineral examples.

[2][3] There is only one tetragonal Bravais lattice in two dimensions: the square lattice.

An example of the tetragonal crystals, wulfenite
Two different views (top down and from the side) of the unit cell of tP 30-CrFe (σ-phase Frank–Kasper structure ) that show its different side lengths, making this structure a member of the tetragonal crystal system.