Crystal Lab › Prototype structures › Tetragonal
Orange (I) HgI₂
Tetragonal · space group I41/amd (No. 141) · Pearson tI48
Symmetry elements and Wyckoff positions (interactive)
Orange (I) HgI₂ in I41/amd
SettingUnit cell
- Lattice constants
- a = 8.786 Å, b = 8.786 Å, c = 24.667 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 1904.3 ų
- Atoms in the conventional cell
- 48 (I 32, Hg 16)
- Formula units Z
- 16
- Pearson symbol
- tI48 — tetragonal, body-centred lattice, 48 atoms per conventional cell
- Symmetry operations
- 32 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| I2 | I | 8e | 8 | 0.0000 | 0.2500 | 0.7575 |
| I3 | I | 8e | 8 | 0.0000 | 0.2500 | 0.2424 |
| I4 | I | 16g | 16 | 0.2358 | 0.4858 | 0.8750 |
| Hg1 | Hg | 16h | 16 | 0.0000 | 0.4979 | 0.3123 |
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 48 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
AB2_tI48_141_h_2eg-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI48, then the space-group number 141, then the Wyckoff letters occupied by each element in turn (I: 8e; I: 8e; I: 16g; Hg: 16h). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Note: Orange (I) HgI₂.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB2_tI48_141_h_2eg-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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