Table 3552a and Figure 3552 show the orthorhombic crystal systems and the schematic illustrations of the orthorhombic lattices, respectively. Furthermore, Table 3552c shows the cell edges and angles of orthorhombic crystals.
Table 3552a. Orthorhombic crystal systems.
Crystal
family |
Crystal
system |
Required
symmetries
of point group |
Point
group |
Space
group |
Bravais
lattices |
Lattice
system |
Orthorhombic |
3 two-fold axes of rotation or 1 two-fold axis of rotation and two mirror planes |
3 |
59 |
4 |
Orthorhombic |

Figure 3552. Schematic illustrations of the Bravais
lattices of orthorhombic crystals.
Table 3552b. Relationship between Laue classes and point groups.
System |
Essential symmetry |
Lattice symmetry |
Laue class (Diffraction symmetry) |
Point Groups (Hermann–Mauguin notation) |
Triclinic |
None |
 |
 |
1, -1 |
Monoclinic |
 |
2/m |
2/m |
2, m, 2/m |
Orthorhombic |
222 or 2mm
|
mmm
|
mmm |
222, mm2, mmm |
Tetragonal |
 |
4/mmm
|
4/m
|
4, -4, 4/m |
4/mmm |
422, -42m, 4mm, 4/mmm |
Trigonal |
 |
 |
3 |
3, -3 |
-3m1 |
321, 3m1, -3m1 |
-31m |
312, 31m, -31m |
Hexagonal |
 |
6/mmm
|
6/m |
6, -6, 6/m |
6/mmm |
622, -62m, 6mm, 6/mmm |
Cubic |
23 |
m3m
|
m-3 |
23, m-3 |
m-3m |
432, -43m, m-3m |
For orthorhombic structures, the lattice spacing (d-spacing) can be given by, (You can download the excel file for your own calculations)
--------------------------------- [3552]
where,
a, b and c -- The lattice constants.
h, k, and l -- The Miller indices.
Table 3554c. Centrosymmetric, non-centrosymmetric, and chiral space groups for orthorhombic lattices. |
Crystal system |
Laue group |
Point group |
Space group |
Orthorhombic |
mmm |
222 |
P222, P2221, P21212, P212121, C222, C2221, I222, I212121, F222 |
mm2 |
Pmm2, Pmc21, Pcc2, Pma2, Pca21, Pnc2, Pmn21, Pba2, Pna21, Pnn2, Cmm2, Cmc21, Ccc2, Amm2, Abm2, Ama2, Aba2, Imm2, Iba2, Ima2, Fmm2, Fdd2 |
mmm |
Pmmm, Pnnn, Pccm, Pban, Pmma, Pnna, Pmna, Pcca, Pbam, Pccn, Pbcm, Pnnm, Pmmn, Pbcn, Pbca, Pnma, Cmcm, Cmca, Cmmm, Cccm, Cmma, Ccca, Immm, Ibam, Ibca, Imma, Fmmm, Fddd |
Red: chiral; green: non-centrosymmetric; and yellow: centrosymmetric. |
Table 3552c. Other characteristics of orthorhombic structures.
Contents |
Page |
Angles in unit cells |
page3555 |
Volume of unit cells |
page3033 |
Bravais lattices |
page4546 |
Relationship between three-dimensional crystal families, crystal systems, space group, point group, lattice systems and symmetries |
page4549 |
|