Orthorhombic crystal system

The orthorhombic crystal system has three mutually perpendicular axes of unequal lengths. Its crystals belong to one of four symmetry classes based on their rotational and reflection symmetries.

Crystal system: A classification of crystals based on unit-cell geometry and symmetry. Orthorhombic is one of the seven systems defined by these geometric and symmetry criteria.
Orthorhombic point groups: The three-dimensional point groups whose symmetry belongs to the orthorhombic crystal system. Their four symmetry classes refine the system beyond its shared axis geometry.
Monoclinic crystal system: A crystal system with three unequal axes, two of which meet at an oblique angle. Monoclinic crystals share unequal axis lengths but lack orthorhombic right-angle geometry.
X-ray crystallography: A method that uses X-ray diffraction to determine the atomic structure of crystals. Diffraction patterns reveal lattice dimensions and symmetry used to assign the orthorhombic system.
Unit cell: The smallest repeating structural unit used to describe a crystal lattice. Its three edge lengths and right angles give the orthorhombic system its defining geometry.
Orthorhombic Bravais lattices: The primitive, base-centered, body-centered, and face-centered lattices with orthorhombic geometry. These four lattice centerings describe distinct ways points can occupy orthorhombic unit cells.
Tetragonal crystal system: A crystal system with three perpendicular axes, two equal in length and one unequal. Tetragonal geometry differs by having two equal axes rather than three unequal ones.
Bravais lattice: One of the distinct three-dimensional periodic lattices that can describe crystal structures. Orthorhombic lattices are four members of the full set of three-dimensional Bravais lattices.
Crystal lattice: An idealized periodic arrangement of points representing positions in a crystal. The orthorhombic unit cell repeats through a lattice to describe crystal periodicity.
Symmetry operation: A transformation that leaves an object or pattern unchanged. Rotations, reflections, and inversion combine to produce orthorhombic crystal symmetries.

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