Crystal Lab › Prototype structures › Cubic
(NH₄)₃AlF₆ (J2₁)
Cubic · space group Fm-3m (No. 225) · Pearson cF200 · Strukturbericht J21
Symmetry elements and Wyckoff positions (interactive)
(NH₄)₃AlF₆ (J2₁) in Fm-3m
SettingUnit cell
- Lattice constants
- a = 8.940 Å, b = 8.940 Å, c = 8.940 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 714.5 ų
- Atoms in the conventional cell
- 200 (Al 4, N 12, F 120, H 64)
- Formula units Z
- 4
- Pearson symbol
- cF200 — cubic, face-centred lattice, 200 atoms per conventional cell
- Symmetry operations
- 192 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Al1 | Al | 4a | 4 | 0.0000 | 0.0000 | 0.0000 |
| N6 | N | 4b | 4 | 0.5000 | 0.5000 | 0.5000 |
| N7 | N | 8c | 8 | 0.2500 | 0.2500 | 0.2500 |
| F2 | F | 24e | 24 | 0.1969 | 0.0000 | 0.0000 |
| H4 | H | 32f | 32 | 0.1930 | 0.1930 | 0.1930 |
| H5 | H | 32f | 32 | 0.5570 | 0.5570 | 0.5570 |
| F3 | F | 96j | 96 | 0.0000 | 0.5536 | 0.6923 |
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 200 atoms drawn above are these sites multiplied by all 192 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
AB30C16D3_cF200_225_a_ej_2f_bc-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol cF200, then the space-group number 225, then the Wyckoff letters occupied by each element in turn (Al: 4a; N: 4b; N: 8c; F: 24e; H: 32f; H: 32f; F: 96j). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
(NH₄)₃FeF₆, (NH₄)₃TiOF₅, (NH₄)₃Fe(NO₂)₆, K₃Ir(NO₂)₆, Cs₃Ir(NO₂)₆, Rb₃Ir(NO₂)₆, Tl₃Ir(NO₂)₆ <!--beginning with an
Note: J2₁.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB30C16D3_cF200_225_a_ej_2f_bc-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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