Crystal Lab › Prototype structures › Hexagonal
CsC₈
Hexagonal · space group P6222 (No. 180) · Pearson hP27
Symmetry elements and Wyckoff positions (interactive)
CsC₈ in P6222
SettingUnit cell
- Lattice constants
- a = 4.960 Å, b = 4.960 Å, c = 17.847 Å; α = 90.00°, β = 90.00°, γ = 120.00°
- Cell volume
- 380.3 ų
- Atoms in the conventional cell
- 27 (Cs 3, C 24)
- Formula units Z
- 3
- Pearson symbol
- hP27 — hexagonal / trigonal, primitive lattice, 27 atoms per conventional cell
- Symmetry operations
- 12 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Cs4 | Cs | 3d | 3 | 0.5000 | 0.0000 | 0.5000 |
| C1 | C | 6i | 6 | 0.6667 | 0.3333 | 0.0000 |
| C2 | C | 6i | 6 | 0.8333 | 0.6667 | 0.0000 |
| C3 | C | 12k | 12 | 0.1667 | 0.3333 | 0.3333 |
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 27 atoms drawn above are these sites multiplied by all 12 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
A8B_hP27_180_2ik_d-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hP27, then the space-group number 180, then the Wyckoff letters occupied by each element in turn (Cs: 3d; C: 6i; C: 6i; C: 12k). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A8B_hP27_180_2ik_d-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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