Crystal Lab › Prototype structures › Trigonal
CrCl₃
Trigonal · space group P3212 (No. 153) · Pearson hP24
Symmetry elements and Wyckoff positions (interactive)
CrCl₃ in P3212
SettingUnit cell
- Lattice constants
- a = 6.017 Å, b = 6.017 Å, c = 17.300 Å; α = 90.00°, β = 90.00°, γ = 120.00°
- Cell volume
- 542.4 ų
- Atoms in the conventional cell
- 24 (Cr 6, Cl 18)
- Formula units Z
- 6
- Pearson symbol
- hP24 — hexagonal / trigonal, primitive lattice, 24 atoms per conventional cell
- Symmetry operations
- 6 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Cr4 | Cr | 3a | 3 | 0.1111 | 0.8889 | 0.6667 |
| Cr5 | Cr | 3a | 3 | 0.4444 | 0.5556 | 0.6667 |
| Cl1 | Cl | 6c | 6 | 0.1111 | 0.2222 | 0.5936 |
| Cl2 | Cl | 6c | 6 | 0.4444 | 0.8888 | 0.5936 |
| Cl3 | Cl | 6c | 6 | 0.7778 | 0.5556 | 0.5936 |
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 6 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
A3B_hP24_153_3c_2a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hP24, then the space-group number 153, then the Wyckoff letters occupied by each element in turn (Cr: 3a; Cr: 3a; Cl: 6c; Cl: 6c; Cl: 6c). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
CrI₃ <!--beginning with an
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A3B_hP24_153_3c_2a-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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