# Difference between revisions of "H centred cell"

### From Online Dictionary of Crystallography

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*[[Centred lattices]] | *[[Centred lattices]] | ||

*[[D centred cell]] | *[[D centred cell]] | ||

− | *Chapter 1.5 of ''International Tables for Crystallography | + | *Chapter 1.5 of ''International Tables for Crystallography, Volume A'', 6th edition |

[[Category:Fundamental crystallography]] | [[Category:Fundamental crystallography]] |

## Revision as of 02:00, 27 August 2017

Maille centrée H (*Fr*). Cella centrata H (*It*). H 複合単位胞 (*Ja*).

The ** H centred cell** (

**triple hexagonal cell**) is an alternative description of the hexagonal Bravais lattice. From the conventional

*hP*cell one obtains the

*hH*cell by taking the new basis vectors by means of one of the following transformation matrices, which give three possible orientations of the

*hH*cell with respect to the

*hP*cell:

*H*_{1}: 110/-120/001 *H*_{2}: 2-10/110/001 *H*_{3}: 1-20/2-10/001

The resulting *hH* cell has centring nodes at 1/3,2/3,0 and 2/3,1/3,0.

Secondary and tertiary elements in the *hP* cell are exchanged in the *hH* cell. For example, the space-group symbol *P*3*m*1 become *H*31*m* when the triple cell is used.

## See also

- Centred lattices
- D centred cell
- Chapter 1.5 of
*International Tables for Crystallography, Volume A*, 6th edition