Crystal Lab › Prototype structures › Tetragonal
ThH₂ (L'2_{b})
Tetragonal · space group I4/mmm (No. 139) · Pearson tI6 · Strukturbericht L'2b
Symmetry elements and Wyckoff positions (interactive)
ThH₂ (L'2_{b}) in I4/mmm
SettingUnit cell
- Lattice constants
- a = 4.100 Å, b = 4.100 Å, c = 5.030 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 84.6 ų
- Atoms in the conventional cell
- 6 (Th 2, H 4)
- Formula units Z
- 2
- Pearson symbol
- tI6 — tetragonal, body-centred lattice, 6 atoms per conventional cell
- Symmetry operations
- 32 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Th2 | Th | 2a | 2 | 0.0000 | 0.0000 | 0.0000 |
| H1 | H | 4d | 4 | 0.0000 | 0.5000 | 0.2500 |
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 6 atoms drawn above are these sites multiplied by all 32 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
A2B_tI6_139_d_a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI6, then the space-group number 139, then the Wyckoff letters occupied by each element in turn (Th: 2a; H: 4d). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
SiPt₂, TiH₂, ZrH₂, Pt₂Si (LT) <!--beginning with an
Note: L'2_{b}.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B_tI6_139_d_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.
← LuNi₂B₂C · Space group I4/mmm (51 prototypes) · All prototypes · CaC₂-I (C11_{a}) →