Crystal Lab › Prototype structures › Orthorhombic
Mg₂Cu (C_{b})
Orthorhombic · space group Fddd (No. 70) · Pearson oF48 · Strukturbericht Cb
Symmetry elements and Wyckoff positions (interactive)
Mg₂Cu (C_{b}) in Fddd
SettingUnit cell
- Lattice constants
- a = 18.328 Å, b = 9.044 Å, c = 5.275 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 874.4 ų
- Atoms in the conventional cell
- 48 (Cu 16, Mg 32)
- Formula units Z
- 16
- Pearson symbol
- oF48 — orthorhombic, face-centred lattice, 48 atoms per conventional cell
- Symmetry operations
- 32 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Cu1 | Cu | 16e | 16 | 0.4982 | 0.1250 | 0.1250 |
| Mg3 | Mg | 16e | 16 | 0.0415 | 0.1250 | 0.1250 |
| Mg2 | Mg | 16f | 16 | 0.1250 | 0.7914 | 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 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_oF48_70_e_ef-002: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oF48, then the space-group number 70, then the Wyckoff letters occupied by each element in turn (Cu: 16e; Mg: 16e; Mg: 16f). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
In₂Ir, NbSn₂, TiBi₂, FeGaGe, SbSnTi <!--beginning with an
Note: C_{b}.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB2_oF48_70_e_ef-002 (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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