Crystal Lab › Prototype structures › Tetragonal
TlZn₂Sb₂
Tetragonal · space group I4 (No. 79) · Pearson tI20
Symmetry elements and Wyckoff positions (interactive)
TlZn₂Sb₂ in I4
SettingUnit cell
- Lattice constants
- a = 8.649 Å, b = 8.649 Å, c = 7.287 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 545.1 ų
- Atoms in the conventional cell
- 20 (Tl 4, Sb 8, Zn 8)
- Formula units Z
- 4
- Pearson symbol
- tI20 — tetragonal, body-centred lattice, 20 atoms per conventional cell
- Symmetry operations
- 8 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Tl2 | Tl | 2a | 2 | 0.0000 | 0.0000 | 0.0000 |
| Tl3 | Tl | 2a | 2 | 0.0000 | 0.0000 | 0.5104 |
| Sb1 | Sb | 8c | 8 | 0.1640 | 0.6630 | 0.7804 |
| Zn4 | Zn | 8c | 8 | 0.1330 | 0.3650 | 0.9144 |
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 20 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
A2BC2_tI20_79_c_2a_c-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI20, then the space-group number 79, then the Wyckoff letters occupied by each element in turn (Tl: 2a; Tl: 2a; Sb: 8c; Zn: 8c). 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 A2BC2_tI20_79_c_2a_c-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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