Crystal Lab › Prototype structures › Hexagonal
Osumilite (KMg₂Al₃Si₁₂O₃₀)
Hexagonal · space group P6/mcc (No. 192) · Pearson hP96 · mineral: osumilite
Symmetry elements and Wyckoff positions (interactive)
Osumilite (KMg₂Al₃Si₁₂O₃₀) in P6/mcc
SettingUnit cell
- Lattice constants
- a = 10.086 Å, b = 10.086 Å, c = 14.325 Å; α = 90.00°, β = 90.00°, γ = 120.00°
- Cell volume
- 1262.0 ų
- Atoms in the conventional cell
- 96 (K 2, Mg 4, Al 6, O 60, Si 24)
- Formula units Z
- 2
- Pearson symbol
- hP96 — hexagonal / trigonal, primitive lattice, 96 atoms per conventional cell
- Symmetry operations
- 24 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| K2 | K | 2a | 2 | 0.0000 | 0.0000 | 0.2500 |
| Mg3 | Mg | 4c | 4 | 0.3333 | 0.6667 | 0.2500 |
| Al1 | Al | 6f | 6 | 0.5000 | 0.0000 | 0.2500 |
| O4 | O | 12l | 12 | 0.1229 | 0.4079 | 0.0000 |
| O5 | O | 24m | 24 | 0.2166 | 0.2847 | 0.1320 |
| O6 | O | 24m | 24 | 0.1398 | 0.4934 | 0.1790 |
| Si7 | Si | 24m | 24 | 0.2482 | 0.3536 | 0.3921 |
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 96 atoms drawn above are these sites multiplied by all 24 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
A3BC2D30E12_hP96_192_f_a_c_l2m_m-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hP96, then the space-group number 192, then the Wyckoff letters occupied by each element in turn (K: 2a; Mg: 4c; Al: 6f; O: 12l; O: 24m; O: 24m; Si: 24m). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Note: Osumilite.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A3BC2D30E12_hP96_192_f_a_c_l2m_m-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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