rectangular lattice

{{Short description|2-dimensional lattice}}

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|+ Rectangular lattices

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Primitive

!Centered

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pmm

!cmm

The rectangular lattice and rhombic lattice (or centered rectangular lattice) constitute two of the five two-dimensional Bravais lattice types.{{Cite web|last=Rana|first=Farhan|title=Lattices in 1D, 2D, and 3D|url=https://courses.cit.cornell.edu/ece407/Lectures/handout4.pdf|url-status=live|archive-url=https://web.archive.org/web/20201218214110/https://courses.cit.cornell.edu/ece407/Lectures/handout4.pdf|archive-date=2020-12-18|website=Cornell University}} The symmetry categories of these lattices are wallpaper groups pmm and cmm respectively. The conventional translation vectors of the rectangular lattices form an angle of 90° and are of unequal lengths.

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Bravais lattices

There are two rectangular Bravais lattices: primitive rectangular and centered rectangular (also rhombic).

File:Rectangular unit cells.svg

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! Bravais lattice

! Rectangular

! Centered rectangular

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! Pearson symbol

| op

| oc

Standard unit cell

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Rhombic unit cell

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The primitive rectangular lattice can also be described by a centered rhombic unit cell, while the centered rectangular lattice can also be described by a primitive rhombic unit cell. Note that the length a in the lower row is not the same as in the upper row. For the first column above, a of the second row equals \sqrt{a^2+b^2} of the first row, and for the second column it equals \frac{1}{2} \sqrt{a^2+b^2}.

Crystal classes

The rectangular lattice class names, Schönflies notation, Hermann-Mauguin notation, orbifold notation, Coxeter notation, and wallpaper groups are listed in the table below.

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colspan=4|Geometric class, point group

! rowspan=2|Arithmetic
class

! rowspan=2 colspan=2|Wallpaper groups

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!Schön.

IntlOrb.Cox.
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|rowspan=2| D1

rowspan=2|mrowspan=2|(*)rowspan=2|[ ]

| Along

| pm
(**)

| pg
(××)

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| Between

| cm
(*×)

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|rowspan=2|D2

rowspan=2|2mmrowspan=2|(*22)rowspan=2|[2]

| Along

| pmm
(*2222)

| pmg
(22*)

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| Between

| cmm
(2*22)

| pgg
(22×)

References

{{reflist}}

{{Crystal systems}}

Category:Lattice points

Category:Crystal systems

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