# Orthorhombic crystal system

Orthorhombic crystal system
An example of the orthorhombic crystals, aragonite

In crystallography, the orthorhombic crystal system is one of the seven lattice point groups. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with a rectangular base (a by b) and height (c), such that a, b, and c are distinct. All three bases intersect at 90° angles. The three lattice vectors remain mutually orthogonal.

## Bravais Lattices

There are four orthorhombic Bravais lattices: simple orthorhombic, base-centered orthorhombic, body-centered orthorhombic, and face-centered orthorhombic.

Orthorhombic Bravais lattices
Primitive Body-centered Base-centered Face-centered

## Crystal Classes

The orthorhombic crystal system class names, examples, Schönflies notation, Hermann-Mauguin notation, point groups, International Tables for Crystallography space group number,[1] orbifold, type, and space groups are listed in the table below.

# Point group Example Type Space groups
Name Schönflies Intl Orbifold Coxeter
16-24 sphenoidal [2] D2 222 222 [2,2]+ epsomite enantiomorphic P222, P2221, P21212, P212121, C2221, C222, F222, I222, I212121
25-46 pyramidal [2] C2v mm2 *22 [2] hemimorphite, bertrandite polar Pmm2, Pmc21, Pcc2, Pma2, Pca21, Pnc2, Pmn21, Pba2, Pna21, Pnn2, Cmm2, Cmc21, Ccc2, Amm2, Aem2, Ama2,Aea2, Fmm2, Fdd2, Imm2, Iba2, Ima2
47-74 bipyramidal [2] D2h mmm *222 [2,2] olivine, aragonite, marcasite centrosymmetric Pmmm, Pnnn, Pccm, Pban, Pmma, Pnna, Pmna, Pcca, Pbam, Pccn, Pbcm, Pnnm, Pmmn, Pbcn, Pbca, Pnma, Cmcm, Cmce, Cmmm, Cccm, Cmme, Ccce, Fmmm, Fddd, Immm, Ibam, Ibca, Imma

## References

• Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., pp. 69 – 73, ISBN 0-471-80580-7
1. ^ Prince, E., ed (2006). International Tables for Crystallography. International Union of Crystallography. doi:10.1107/97809553602060000001. ISBN 978-1-4020-4969-9.
2. ^ a b c

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