Crystal Lab › Prototype structures › Hexagonal
Cr-233 Quasi-One-Dimensional Superconductor (K₂Cr₃As₃)
Hexagonal · space group P-6m2 (No. 187) · Pearson hP16
Symmetry elements and Wyckoff positions (interactive)
Cr-233 Quasi-One-Dimensional Superconductor (K₂Cr₃As₃) in P-6m2
SettingUnit cell
- Lattice constants
- a = 9.983 Å, b = 9.983 Å, c = 4.230 Å; α = 90.00°, β = 90.00°, γ = 120.00°
- Cell volume
- 365.1 ų
- Atoms in the conventional cell
- 16 (K 4, As 6, Cr 6)
- Formula units Z
- 2
- Pearson symbol
- hP16 — hexagonal / trigonal, primitive lattice, 16 atoms per conventional cell
- Symmetry operations
- 12 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| K5 | K | 1a | 1 | 0.0000 | 0.0000 | 0.0000 |
| As1 | As | 3j | 3 | 0.5006 | 0.4994 | 0.0000 |
| Cr3 | Cr | 3j | 3 | 0.7565 | 0.2435 | 0.0000 |
| As2 | As | 3k | 3 | 0.8343 | 0.1657 | 0.5000 |
| Cr4 | Cr | 3k | 3 | 0.5794 | 0.4206 | 0.5000 |
| K6 | K | 3k | 3 | 0.2054 | 0.7946 | 0.5000 |
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 16 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
A3B3C2_hP16_187_jk_jk_ak-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hP16, then the space-group number 187, then the Wyckoff letters occupied by each element in turn (K: 1a; As: 3j; Cr: 3j; As: 3k; Cr: 3k; K: 3k). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
Cs₂Cr₃As₃, K₂Mo₃As₃, Rb₂Cr₃As₃, Rb₂Mo₃As₃ <!--beginning with an
Note: Quasi-1D Superconductor.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A3B3C2_hP16_187_jk_jk_ak-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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