Editing Tetragonal crystal system (section)

{{short description|Lattice point group}}
{{refimprove|date=July 2011}}
{{redirect|Tetragonal|other uses|tetragon}}
[[File:WulfeniteUSGOV.jpg|thumb|right|200px|An example of the tetragonal crystals, [[wulfenite]]]]
[[File:TP30-CrFe crystalmaker.pdf|thumb|right|300px|Two different views (top down and from the side) of the unit cell of ''tP''30-CrFe (σ-phase [[Frank–Kasper phases|Frank–Kasper structure]]) that show its different side lengths, making this structure a member of the tetragonal crystal system.]]
In [[crystallography]], the '''tetragonal crystal system'''  is one of the 7 [[crystal system]]s. Tetragonal [[crystal lattice]]s result from stretching a cubic lattice along one of its lattice vectors, so that the [[Cube (geometry)|cube]] becomes a rectangular [[Prism (geometry)|prism]] with a square base (''a'' by ''a'') and height (''c'', which is different from ''a'').