Crystal Lab › Prototype structures › Tetragonal
Y-MgNiSn
Tetragonal · space group P42cm (No. 101) · Pearson tP32
Symmetry elements and Wyckoff positions (interactive)
Y-MgNiSn in P42cm
SettingUnit cell
- Lattice constants
- a = 9.851 Å, b = 9.851 Å, c = 6.868 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 666.5 ų
- Atoms in the conventional cell
- 32 (Mg 14, Ni 14, Sn 4)
- Formula units Z
- 2
- Pearson symbol
- tP32 — tetragonal, primitive lattice, 32 atoms per conventional cell
- Symmetry operations
- 8 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Mg1 | Mg | 2a | 2 | 0.0000 | 0.0000 | 0.0730 |
| Ni4 | Ni | 2b | 2 | 0.5000 | 0.5000 | 0.1038 |
| Mg2 | Mg | 4d | 4 | 0.2254 | 0.2254 | 0.7328 |
| Ni5 | Ni | 4d | 4 | 0.3093 | 0.3093 | 0.0644 |
| Sn7 | Sn | 4d | 4 | 0.1714 | 0.1714 | 0.3336 |
| Mg3 | Mg | 8e | 8 | 0.2384 | 0.4756 | 0.3471 |
| Ni6 | Ni | 8e | 8 | 0.0352 | 0.3449 | 0.0449 |
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 32 atoms drawn above are these sites multiplied by all 8 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
A7B7C2_tP32_101_ade_bde_d-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tP32, then the space-group number 101, then the Wyckoff letters occupied by each element in turn (Mg: 2a; Ni: 2b; Mg: 4d; Ni: 4d; Sn: 4d; Mg: 8e; Ni: 8e). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Note: Y-MgNiSn.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A7B7C2_tP32_101_ade_bde_d-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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