Crystal Lab › Prototype structures › Tetragonal
α-AlB₁₂
Tetragonal · space group P43212 (No. 96) · Pearson tP216
Symmetry elements and Wyckoff positions (interactive)
α-AlB₁₂ in P43212
SettingUnit cell
- Lattice constants
- a = 10.158 Å, b = 10.158 Å, c = 14.270 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 1472.4 ų
- Atoms in the conventional cell
- 216 (B 176, Al 40)
- Formula units Z
- 8
- Pearson symbol
- tP216 — tetragonal, primitive lattice, 216 atoms per conventional cell
- Symmetry operations
- 8 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| B6 | B | 4a | 4 | 0.6683 | 0.6683 | 0.0000 |
| B7 | B | 4a | 4 | 0.9646 | 0.9646 | 0.0000 |
| Al1 | Al | 8b | 8 | 0.3021 | 0.3688 | 0.2589 |
| Al2 | Al | 8b | 8 | 0.0823 | 0.0118 | 0.3086 |
| Al3 | Al | 8b | 8 | 0.3130 | 0.3932 | 0.3419 |
| Al4 | Al | 8b | 8 | 0.2873 | 0.4785 | 0.1224 |
| Al5 | Al | 8b | 8 | 0.3037 | 0.3831 | 0.2958 |
| B10 | B | 8b | 8 | 0.9545 | 0.3119 | 0.2317 |
| B11 | B | 8b | 8 | 0.9585 | 0.3939 | 0.1179 |
| B12 | B | 8b | 8 | 0.9796 | 0.1091 | 0.0808 |
| B13 | B | 8b | 8 | 0.9691 | 0.2740 | 0.0296 |
| B14 | B | 8b | 8 | 0.1073 | 0.2231 | 0.2456 |
| B15 | B | 8b | 8 | 0.1034 | 0.3895 | 0.1917 |
| B16 | B | 8b | 8 | 0.1217 | 0.1034 | 0.1549 |
| B17 | B | 8b | 8 | 0.1219 | 0.1920 | 0.0447 |
| B18 | B | 8b | 8 | 0.1137 | 0.3628 | 0.0647 |
| B19 | B | 8b | 8 | 0.2054 | 0.2596 | 0.1391 |
| B20 | B | 8b | 8 | 0.3140 | 0.0579 | 0.3606 |
| B21 | B | 8b | 8 | 0.3860 | 0.2072 | 0.3252 |
| B22 | B | 8b | 8 | 0.2038 | 0.1968 | 0.3452 |
| B23 | B | 8b | 8 | 0.4671 | 0.1174 | 0.4112 |
| B24 | B | 8b | 8 | 0.4596 | 0.2933 | 0.4220 |
| B25 | B | 8b | 8 | 0.1856 | 0.0933 | 0.4486 |
| B26 | B | 8b | 8 | 0.2708 | 0.1782 | 0.5459 |
| B27 | B | 8b | 8 | 0.3478 | 0.0396 | 0.4913 |
| B28 | B | 8b | 8 | 0.4392 | 0.1893 | 0.5252 |
| B8 | B | 8b | 8 | 0.8723 | 0.2394 | 0.1282 |
| B9 | B | 8b | 8 | 0.9605 | 0.1359 | 0.2091 |
The multiplicity and the Wyckoff letter say how many copies of the site the group makes in one cell and on which kind of symmetry element the site sits; the 216 atoms drawn above are these sites multiplied by all 8 operations. Press Wyckoff under Colour to see the sites, and tick a symmetry element on the left to see which atoms lie on it.
How to read the label
A5B22_tP216_96_5b_2a21b-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tP216, then the space-group number 96, then the Wyckoff letters occupied by each element in turn (B: 4a; B: 4a; Al: 8b; Al: 8b; Al: 8b; Al: 8b; Al: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Note: α-AlB₁₂.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A5B22_tP216_96_5b_2a21b-001 (M. J. Mehl et al., Comput. Mater. Sci. 136, S1 (2017); D. Hicks et al., ibid. 161, S1 (2019) and 199, 110450 (2021); S. Eckert et al., ibid. 240, 112988 (2024)). Symmetry elements, Wyckoff assignment and the diagram are computed on this page from the group operations.
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