Crystal Lab › Prototype structures › Trigonal
GeSb₂Te₄
Trigonal · space group R-3m (No. 166) · Pearson hR7
Symmetry elements and Wyckoff positions (interactive)
GeSb₂Te₄ in R-3m
SettingUnit cell
- Lattice constants
- a = 4.210 Å, b = 4.210 Å, c = 40.600 Å; α = 90.00°, β = 90.00°, γ = 120.00°
- Cell volume
- 623.2 ų
- Atoms in the conventional cell
- 21 (Ge 3, Sb 6, Te 12)
- Formula units Z
- 3
- Pearson symbol
- hR7 — hexagonal / trigonal, rhombohedral lattice, 7 atoms per conventional cell
- Symmetry operations
- 36 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Ge1 | Ge | 3a | 3 | 0.0000 | 0.0000 | 0.0000 |
| Sb2 | Sb | 6c | 6 | 0.0000 | 0.0000 | 0.1440 |
| Te3 | Te | 6c | 6 | 0.0000 | 0.0000 | 0.2900 |
| Te4 | Te | 6c | 6 | 0.0000 | 0.0000 | 0.4320 |
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 21 atoms drawn above are these sites multiplied by all 36 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
AB2C4_hR7_166_a_c_2c-002: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hR7, then the space-group number 166, then the Wyckoff letters occupied by each element in turn (Ge: 3a; Sb: 6c; Te: 6c; Te: 6c). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
GeAs₂Te₄, GeBi₂Te₄, PbBi₂Te₄, PbSb₂Te₄, SnBi₂Te₄, SnSb₂Te₄, TeS₂Bi₄, BiSbSnTe₄, Bi₂Sb₂Te₃ <!--beginning with an
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB2C4_hR7_166_a_c_2c-002 (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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