Crystal Lab › Prototype structures › Tetragonal
α-ThCl₄ Cl₄Th
Tetragonal · space group I41/a (No. 88) · Pearson tI20
Symmetry elements and Wyckoff positions (interactive)
α-ThCl₄ in I41/a
SettingUnit cell
- Lattice constants
- a = 6.408 Å, b = 6.408 Å, c = 12.924 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 530.7 ų
- Atoms in the conventional cell
- 20 (Th 4, Cl 16)
- Formula units Z
- 4
- Pearson symbol
- tI20 — tetragonal, body-centred lattice, 20 atoms per conventional cell
- Symmetry operations
- 16 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Th2 | Th | 4a | 4 | 0.0000 | 0.2500 | 0.1250 |
| Cl1 | Cl | 16f | 16 | 0.1470 | 0.0170 | 0.2980 |
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 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
A4B_tI20_88_f_a-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 88, then the Wyckoff letters occupied by each element in turn (Th: 4a; Cl: 16f). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
ThBr₄ <!--beginning with an
Note: α-ThCl₄.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A4B_tI20_88_f_a-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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