Difference between revisions of "H centred cell"
From Online Dictionary of Crystallography
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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: | 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''<sub>1</sub>: | + | ''H''<sub>1</sub>: 1-10/-120/001 ''H''<sub>2</sub>: 2-10/110/001 ''H''<sub>3</sub>: 1-20/2-10/001 |
The resulting ''hH'' cell has centring nodes at 1/3,2/3,0 and 2/3,1/3,0. | The resulting ''hH'' cell has centring nodes at 1/3,2/3,0 and 2/3,1/3,0. | ||
Revision as of 05:24, 10 June 2015
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:
H1: 1-10/-120/001 H2: 2-10/110/001 H3: 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 P3m1 become H31m when the triple cell is used.
See also
- Centred lattices
- D centred cell
- Section 4.3.5.3 in the International Tables for Crystallography, Volume A
- Chapter 5 in the International Tables for Crystallography, Volume A