Crystal Lab › Prototype structures › Trigonal
Cs₃As₂Cl₉ (K7₃)
Trigonal · space group P321 (No. 150) · Pearson hP14 · Strukturbericht K73
Symmetry elements and Wyckoff positions (interactive)
Cs₃As₂Cl₉ (K7₃) in P321
SettingUnit cell
- Lattice constants
- a = 7.370 Å, b = 7.370 Å, c = 8.910 Å; α = 90.00°, β = 90.00°, γ = 120.00°
- Cell volume
- 419.1 ų
- Atoms in the conventional cell
- 14 (Cs 3, As 2, Cl 9)
- Formula units Z
- 1
- Pearson symbol
- hP14 — hexagonal / trigonal, primitive lattice, 14 atoms per conventional cell
- Symmetry operations
- 6 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Cs4 | Cs | 1a | 1 | 0.0000 | 1.0000 | 0.0000 |
| As1 | As | 2d | 2 | 0.3333 | 0.6667 | 0.8050 |
| Cs5 | Cs | 2d | 2 | 0.3333 | 0.6667 | 0.3200 |
| Cl2 | Cl | 3e | 3 | 0.4800 | 1.0000 | 0.0000 |
| Cl3 | Cl | 6g | 6 | 0.3650 | 0.2000 | 0.3250 |
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 14 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
A2B9C3_hP14_150_d_eg_ad-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hP14, then the space-group number 150, then the Wyckoff letters occupied by each element in turn (Cs: 1a; As: 2d; Cs: 2d; Cl: 3e; Cl: 6g). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Note: K7₃.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B9C3_hP14_150_d_eg_ad-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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