Orthorhombic crystal system
(Redirected from
Orthorhombic
)In
orthogonal
.
Bravais lattices
There are four orthorhombic Bravais lattices: primitive orthorhombic, base-centered orthorhombic, body-centered orthorhombic, and face-centered orthorhombic.
Bravais lattice | Primitive orthorhombic |
Base-centered orthorhombic |
Body-centered orthorhombic |
Face-centered orthorhombic |
---|---|---|---|---|
Pearson symbol | oP | oS | oI | oF |
Unit cell |
For the base-centered orthorhombic lattice, the
primitive cell has the shape of a right rhombic prism;[1]
it can be constructed because the two-dimensional centered rectangular base layer can also be described with primitive rhombic axes. Note that the length of the primitive cell below equals of the conventional cell above.
Crystal classes
The orthorhombic crystal system class names, examples,
Hermann-Mauguin notation, point groups, International Tables for Crystallography space group number,[2] orbifold notation, type, and space groups
are listed in the table below.
№ | Point group | Type | Example | Space groups | |||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Name[3] | Schön. | Intl
|
Orb. | Cox. | Primitive | Base-centered | Face-centered | Body-centered | |||
16–24 | Rhombic disphenoidal | D2 (V) | 222 | 222 | [2,2]+ | Enantiomorphic
|
Epsomite | P222, P2221, P21212, P212121 | C2221, C222 | F222 | I222, I212121 |
25–46 | Rhombic pyramidal | C2v | mm2 | *22 | [2] | Polar | Hemimorphite, bertrandite | Pmm2, Pmc21, Pcc2, Pma2, Pca21, Pnc2, Pmn21, Pba2, Pna21, Pnn2 | Cmm2, Cmc21, Ccc2 Amm2, Aem2, Ama2, Aea2 |
Fmm2, Fdd2 | Imm2, Iba2, Ima2 |
47–74 | Rhombic dipyramidal | D2h (Vh) | 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 |
In two dimensions
In two dimensions there are two orthorhombic Bravais lattices: primitive rectangular and centered rectangular.
Bravais lattice | Rectangular | Centered rectangular |
---|---|---|
Pearson symbol | op | oc |
Unit cell |
See also
- Crystal structure
- Crystal system
- Overview of all space groups
References
- ^ See Hahn (2002), p. 746, row oC, column Primitive, where the cell parameters are given as a1 = a2, α = β = 90°
- S2CID 146060934.
- ^ "The 32 crystal classes". Retrieved 2018-06-19.
Further reading
- Hurlbut, Cornelius S.; Klein, Cornelis (1985). Manual of Mineralogy (20th ed.). pp. 69–73. ISBN 0-471-80580-7.
- Hahn, Theo, ed. (2002). International Tables for Crystallography, Volume A: Space Group Symmetry. International Tables for Crystallography. Vol. A (5th ed.). Berlin, New York: ISBN 978-0-7923-6590-7.