Crystal Lab › Prototype structures › Orthorhombic
Krennerite (AuTe₂)
Orthorhombic · space group Pma2 (No. 28) · Pearson oP24 · mineral: krennerite
Symmetry elements and Wyckoff positions (interactive)
Krennerite (AuTe₂) in Pma2
SettingUnit cell
- Lattice constants
- a = 16.540 Å, b = 8.820 Å, c = 4.460 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 650.6 ų
- Atoms in the conventional cell
- 24 (Au 8, Te 16)
- Formula units Z
- 8
- Pearson symbol
- oP24 — orthorhombic, primitive lattice, 24 atoms per conventional cell
- Symmetry operations
- 4 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Au1 | Au | 2a | 2 | 0.0000 | 0.0000 | 0.0000 |
| Au2 | Au | 2c | 2 | 0.2500 | 0.3190 | 0.0140 |
| Te4 | Te | 2c | 2 | 0.2500 | 0.0180 | 0.0420 |
| Te5 | Te | 2c | 2 | 0.2500 | 0.6170 | 0.0420 |
| Au3 | Au | 4d | 4 | 0.1240 | 0.6660 | 0.5000 |
| Te6 | Te | 4d | 4 | 0.0030 | 0.6990 | 0.0420 |
| Te7 | Te | 4d | 4 | 0.1320 | 0.3640 | 0.5000 |
| Te8 | Te | 4d | 4 | 0.1190 | 0.9640 | 0.5000 |
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 24 atoms drawn above are these sites multiplied by all 4 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_oP24_28_acd_2c3d-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP24, then the space-group number 28, then the Wyckoff letters occupied by each element in turn (Au: 2a; Au: 2c; Te: 2c; Te: 2c; Au: 4d; Te: 4d; Te: 4d; Te: 4d). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Note: Krennerite.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB2_oP24_28_acd_2c3d-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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