Crystal Lab › Prototype structures › Orthorhombic
γ-Alane (AlH₃)
Orthorhombic · space group Pnnm (No. 58) · Pearson oP24 · mineral: gamma-alane
Symmetry elements and Wyckoff positions (interactive)
γ-Alane (AlH₃) in Pnnm
SettingUnit cell
- Lattice constants
- a = 5.381 Å, b = 7.356 Å, c = 5.775 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 228.6 ų
- Atoms in the conventional cell
- 24 (Al 6, H 18)
- Formula units Z
- 6
- Pearson symbol
- oP24 — orthorhombic, primitive lattice, 24 atoms per conventional cell
- Symmetry operations
- 8 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Al1 | Al | 2a | 2 | 0.0000 | 0.0000 | 0.0000 |
| H3 | H | 2c | 2 | 0.0000 | 0.5000 | 0.0000 |
| Al2 | Al | 4g | 4 | 0.7125 | 0.5849 | 0.0000 |
| H4 | H | 4g | 4 | 0.8740 | 0.7780 | 0.0000 |
| H5 | H | 4g | 4 | 0.4060 | 0.6300 | 0.0000 |
| H6 | H | 8h | 8 | 0.7380 | 0.5780 | 0.6910 |
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 24 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
AB3_oP24_58_ag_c2gh-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP24, then the space-group number 58, then the Wyckoff letters occupied by each element in turn (Al: 2a; H: 2c; Al: 4g; H: 4g; H: 4g; H: 8h). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Note: \gamma-Alane.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB3_oP24_58_ag_c2gh-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.
← Marcasite (FeS₂, C18) · Space group Pnnm (16 prototypes) · All prototypes · Adamite [Zn₂(AsO₄)(OH), H2_7] →