Crystal Lab › Prototype structures › Orthorhombic
Tb₃Sn₇
Orthorhombic · space group Cmmm (No. 65) · Pearson oC28
Symmetry elements and Wyckoff positions (interactive)
Tb₃Sn₇ in Cmmm
SettingUnit cell
- Lattice constants
- a = 26.347 Å, b = 4.363 Å, c = 4.441 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 510.5 ų
- Atoms in the conventional cell
- 28 (Tb 6, Sn 22)
- Formula units Z
- 2
- Pearson symbol
- oC28 — orthorhombic, base-centred lattice, 28 atoms per conventional cell
- Symmetry operations
- 16 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Tb7 | Tb | 2a | 2 | 0.0000 | 0.0000 | 0.0000 |
| Sn1 | Sn | 2c | 2 | 0.5000 | 0.0000 | 0.5000 |
| Sn2 | Sn | 4g | 4 | 0.4047 | 0.0000 | 0.0000 |
| Sn3 | Sn | 4g | 4 | 0.2177 | 0.0000 | 0.0000 |
| Sn4 | Sn | 4g | 4 | 0.1831 | 0.0000 | 0.0000 |
| Sn5 | Sn | 4g | 4 | 0.2450 | 0.0000 | 0.0000 |
| Sn6 | Sn | 4h | 4 | 0.1010 | 0.0000 | 0.5000 |
| Tb8 | Tb | 4h | 4 | 0.3090 | 0.0000 | 0.5000 |
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 28 atoms drawn above are these sites multiplied by all 16 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
A11B3_oC28_65_c4gh_ah-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oC28, then the space-group number 65, then the Wyckoff letters occupied by each element in turn (Tb: 2a; Sn: 2c; Sn: 4g; Sn: 4g; Sn: 4g; Sn: 4g; Sn: 4h; Tb: 4h). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
Dy₃Sn₇, Gd₃Sn₇ <!--beginning with an
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A11B3_oC28_65_c4gh_ah-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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