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Na_{24-delta}Ge₁₃₆ Clathrate Ge₁₇Na₃
Cubic · space group Fd-3m (No. 227) · Pearson cF160
Symmetry elements and Wyckoff positions (interactive)
Na_{24-delta}Ge₁₃₆ Clathrate in Fd-3m
SettingUnit cell
- Lattice constants
- a = 15.441 Å, b = 15.441 Å, c = 15.441 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 3681.4 ų
- Atoms in the conventional cell
- 160 (Ge 136, Na 24)
- Formula units Z
- 8
- Pearson symbol
- cF160 — cubic, face-centred lattice, 160 atoms per conventional cell
- Symmetry operations
- 192 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Ge1 | Ge | 8a | 8 | 0.1250 | 0.1250 | 0.1250 |
| Na4 | Na | 8b | 8 | 0.3750 | 0.3750 | 0.3750 |
| Na5 | Na | 16c | 16 | 0.0000 | 0.0000 | 0.0000 |
| Ge2 | Ge | 32e | 32 | 0.2182 | 0.2182 | 0.2182 |
| Ge3 | Ge | 96g | 96 | 0.0674 | 0.0674 | 0.3715 |
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 160 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
A17B3_cF160_227_aeg_bc-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol cF160, then the space-group number 227, then the Wyckoff letters occupied by each element in turn (Ge: 8a; Na: 8b; Na: 16c; Ge: 32e; Ge: 96g). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A17B3_cF160_227_aeg_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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