Crystal Lab › Prototype structures › Tetragonal
CdAs₂
Tetragonal · space group I4122 (No. 98) · Pearson tI12
Symmetry elements and Wyckoff positions (interactive)
CdAs₂ in I4122
SettingUnit cell
- Lattice constants
- a = 7.953 Å, b = 7.953 Å, c = 4.676 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 295.8 ų
- Atoms in the conventional cell
- 12 (Cd 4, As 8)
- Formula units Z
- 4
- Pearson symbol
- tI12 — tetragonal, body-centred lattice, 12 atoms per conventional cell
- Symmetry operations
- 16 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Cd2 | Cd | 4a | 4 | 0.0000 | 0.0000 | 0.0000 |
| As1 | As | 8f | 8 | 0.4400 | 0.2500 | 0.1250 |
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 12 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
A2B_tI12_98_f_a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI12, then the space-group number 98, then the Wyckoff letters occupied by each element in turn (Cd: 4a; As: 8f). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
CdAs_{2-x}P_{x} <!--beginning with an
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B_tI12_98_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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