Crystal Lab › Prototype structures › Trigonal
La₄Ge₃S₁₂
Trigonal · space group R3c (No. 161) · Pearson hR38
Symmetry elements and Wyckoff positions (interactive)
La₄Ge₃S₁₂ in R3c
SettingUnit cell
- Lattice constants
- a = 19.400 Å, b = 19.400 Å, c = 8.100 Å; α = 90.00°, β = 90.00°, γ = 120.00°
- Cell volume
- 2640.1 ų
- Atoms in the conventional cell
- 114 (La 24, Ge 18, S 72)
- Formula units Z
- 6
- Pearson symbol
- hR38 — hexagonal / trigonal, rhombohedral lattice, 38 atoms per conventional cell
- Symmetry operations
- 18 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| La2 | La | 6a | 6 | 0.0000 | 0.0000 | 0.0000 |
| Ge1 | Ge | 18b | 18 | 0.2000 | 0.1875 | 0.1523 |
| La3 | La | 18b | 18 | 0.0030 | 0.2307 | 0.2028 |
| S4 | S | 18b | 18 | 0.1549 | 0.3789 | 0.1618 |
| S5 | S | 18b | 18 | 0.1246 | 0.0643 | 0.2511 |
| S6 | S | 18b | 18 | 0.1145 | 0.2005 | 0.9974 |
| S7 | S | 18b | 18 | 0.3960 | 0.0593 | 0.1817 |
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 114 atoms drawn above are these sites multiplied by all 18 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
A3B4C12_hR38_161_b_ab_4b-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hR38, then the space-group number 161, then the Wyckoff letters occupied by each element in turn (La: 6a; Ge: 18b; La: 18b; S: 18b; S: 18b; S: 18b; S: 18b). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
Ce₄Ge₃S₁₂, Ce₄Si₃S₁₂, Fe₄C₃O₁₂, Gd₄Ge₃S₁₂, Gd₄Si₃S₁₂, Nd₄Ge₃S₁₂, Nd₄Si₃S₁₂, Pr₄Ge₃S₁₂, Pr₄Si₃S₁₂, Sm₄Ge₃S₁₂, Sm₄Si₃S₁₂ <!--beginning with an
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A3B4C12_hR38_161_b_ab_4b-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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