Crystal Lab › Prototype structures › Hexagonal
Al₇C₃N₃
Hexagonal · space group P63mc (No. 186) · Pearson hP26
Symmetry elements and Wyckoff positions (interactive)
Al₇C₃N₃ in P63mc
SettingUnit cell
- Lattice constants
- a = 3.227 Å, b = 3.227 Å, c = 31.700 Å; α = 90.00°, β = 90.00°, γ = 120.00°
- Cell volume
- 285.8 ų
- Atoms in the conventional cell
- 26 (Al 14, C 6, Ni 6)
- Formula units Z
- 2
- Pearson symbol
- hP26 — hexagonal / trigonal, primitive lattice, 26 atoms per conventional cell
- Symmetry operations
- 12 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Al1 | Al | 2a | 2 | 0.0000 | 0.0000 | 0.1085 |
| Al2 | Al | 2a | 2 | 0.0000 | 0.0000 | 0.2615 |
| Al3 | Al | 2a | 2 | 0.0000 | 0.0000 | 0.3915 |
| C8 | C | 2a | 2 | 0.0000 | 0.0000 | 0.0009 |
| C9 | C | 2a | 2 | 0.0000 | 0.0000 | 0.3267 |
| Ni11 | Ni | 2a | 2 | 0.0000 | 0.0000 | 0.1686 |
| Al4 | Al | 2b | 2 | 0.3333 | 0.6667 | 0.5299 |
| Al5 | Al | 2b | 2 | 0.3333 | 0.6667 | 0.6844 |
| Al6 | Al | 2b | 2 | 0.3333 | 0.6667 | 0.8166 |
| Al7 | Al | 2b | 2 | 0.3333 | 0.6667 | 0.9659 |
| C10 | C | 2b | 2 | 0.3333 | 0.6667 | 0.7448 |
| Ni12 | Ni | 2b | 2 | 0.3333 | 0.6667 | 0.5939 |
| Ni13 | Ni | 2b | 2 | 0.3333 | 0.6667 | 0.9069 |
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 26 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
A7B3C3_hP26_186_3a4b_2ab_a2b-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hP26, then the space-group number 186, then the Wyckoff letters occupied by each element in turn (Al: 2a; Al: 2a; Al: 2a; C: 2a; C: 2a; Ni: 2a; Al: 2b; Al: 2b; Al: 2b; Al: 2b; C: 2b; Ni: 2b; Ni: 2b). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
(Al_{7-x}Si_{x})(O_{y}C_{z}N_{6-y-z}) <!--beginning with an
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A7B3C3_hP26_186_3a4b_2ab_a2b-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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