Orthorhombic crystal system
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.
Contents
 Bravais lattices 1
 Crystal classes 2
 See also 3
 References 4
Bravais lattices
There are four orthorhombic Bravais lattices: simple orthorhombic, bodycentered orthorhombic, basecentered orthorhombic, and facecentered orthorhombic.
Name 
Primitive (P) 
Bodycentered (I) 
Basecentered (A, B or C) 
Facecentered (F) 

Pearson symbol  oP  oI  oS  oF 
Unit cell 
Crystal classes
The orthorhombic crystal system class names, examples, Schönflies notation, HermannMauguin notation, point groups, International Tables for Crystallography space group number,^{[1]} orbifold notation, type, and space groups are listed in the table below.
#  Point group 
Type (Example) 
Space groups  

Name  Schön.  Intl  Orb.  Cox.  
1624  sphenoidal ^{[2]}  D_{2}  222  222  [2,2]^{+} 
enantiomorphic (epsomite) 
P222, P222_{1}, P2_{1}2_{1}2, P2_{1}2_{1}2_{1} C222_{1}, C222 F222 I222, I2_{1}2_{1}2_{1} 
2546  pyramidal ^{[2]}  C_{2v}  mm2  *22  [2] 
polar (hemimorphite, bertrandite) 
Pmm2, Pmc2_{1}, Pcc2, Pma2, Pca2_{1}, Pnc2, Pmn2_{1}, Pba2, Pna2_{1}, Pnn2 Cmm2, Cmc2_{1}, Ccc2 Amm2, Aem2, Ama2, Aea2 Fmm2, Fdd2 Imm2, Iba2, Ima2 
4774  bipyramidal ^{[2]}  D_{2h}  mmm  *222  [2,2] 
centrosymmetric (olivine, aragonite, marcasite) 
Pmmm, Pnnn, Pccm, Pban, Pmma, Pnna, Pmna, Pcca, Pbam, Pccn, Pbcm, Pnnm, Pmmn, Pbcn, Pbca, Pnma Cmcm, Cmca, Cmmm, Cccm, Cmme, Ccce Fmmm, Fddd Immm, Ibam, Ibca, Imma 
See also
References
 Hurlbut, Cornelius S.; Klein, Cornelis (1985). Manual of Mineralogy (20th ed.). pp. 69 – 73.
 ^ Prince, E., ed. (2006). International Tables for Crystallography. International Union of Crystallography.
 ^ ^{a} ^{b} ^{c} "The 32 crystal classes". Retrieved 20090708.
