Crystal Lab › Prototype structures › Tetragonal
α-CuAlCl₄ AlCl₄Cu
Tetragonal · space group P-42c (No. 112) · Pearson tP12
Symmetry elements and Wyckoff positions (interactive)
α-CuAlCl₄ in P-42c
SettingUnit cell
- Lattice constants
- a = 5.441 Å, b = 5.441 Å, c = 10.113 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 299.4 ų
- Atoms in the conventional cell
- 12 (Al 2, Cu 2, Cl 8)
- Formula units Z
- 2
- Pearson symbol
- tP12 — tetragonal, primitive lattice, 12 atoms per conventional cell
- Symmetry operations
- 8 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Al1 | Al | 2b | 2 | 0.5000 | 0.0000 | 0.2500 |
| Cu3 | Cu | 2e | 2 | 0.0000 | 0.0000 | 0.0000 |
| Cl2 | Cl | 8n | 8 | 0.2334 | 0.2761 | 0.6295 |
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 12 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
AB4C_tP12_112_b_n_e-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tP12, then the space-group number 112, then the Wyckoff letters occupied by each element in turn (Al: 2b; Cu: 2e; Cl: 8n). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
α-CuAlBr₄, α-CuAlCl₂Br₂, α-CuAlCl₃Br, α-CuAlClBr₃, α-CuGaBr₄, α-CuGaCl₄ <!--beginning with an
Note: α-CuAlCl₄.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB4C_tP12_112_b_n_e-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.