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 90Â° angles. the three lattice vectors remain mutually orthogonal. ==bravais lattices== there are four orthorhombic bravais lattices: simple orthorhombic, body-centered orthorhombic, base-centered orthorhombic, and face-centered orthorhombic. {| class="wikitable" |+ orthorhombic bravais lattices |- !name ! primitive(p) ! body-centered(i) ! base-centered(a, b or c) ! face-centered(f) |- !pearson symbol !op !oi !os !of |- !unit cell || orthohombic, simple || orthohombic, body-centered || orthohombic, base-centered || orthohombic, face-centered |} ==crystal classes== the orthorhombic crystal system class names, examples, schÃ¶nflies notation, hermann-mauguin notation, point groups, international tables for crystallography space group number, orbifold notation, type, and space groups are listed in the table below. {| class=wikitable |- align=center ! rowspan=2 width=50|# ! colspan=5|point group ! rowspan=2|type(example) ! rowspan=2|space groups |- ! name ! schÃ¶n. ! intl ! orb. !cox.&nbsp; |- align=center !16-24 | sphenoidal || d2|| 222|| 222|| [2,2]+ || enantiomorphic(epsomite) |align=left| p222, p2221, p21212, p212121c2221, c222f222i222, i212121 |- align=center !25-46 | pyramidal || c2v||mm2|| *22|| [2] || polar(hemimorphite, bertrandite) |align=left| pmm2, pmc21, pcc2, pma2, pca21, pnc2, pmn21, pba2, pna21, pnn2cmm2, cmc21, ccc2amm2, aem2, ama2, aea2fmm2, fdd2imm2, iba2, ima2 |- align=center ! 47-74 | bipyramidal  || d2h|| mmm|| *222|| [2,2] || centrosymmetric(olivine, aragonite, marcasite) |align=left| pmmm, pnnn, pccm, pban, pmma, pnna, pmna, pcca, pbam, pccn, pbcm, pnnm, pmmn, pbcn, pbca, pnmacmcm, cmca, cmmm, cccm, cmme, cccefmmm, fdddimmm, ibam, ibca, imma |} ==see also== *[[crystal stru
Crystallography