Crystal Lab › Prototype structures › Orthorhombic
Ga₂Mg₅ (D8_{g})
Orthorhombic · space group Ibam (No. 72) · Pearson oI28 · Strukturbericht D8g
Symmetry elements and Wyckoff positions (interactive)
Ga₂Mg₅ (D8_{g}) in Ibam
SettingUnit cell
- Lattice constants
- a = 13.700 Å, b = 7.010 Å, c = 6.020 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 578.1 ų
- Atoms in the conventional cell
- 28 (Mg 20, Ga 8)
- Formula units Z
- 4
- Pearson symbol
- oI28 — orthorhombic, body-centred lattice, 28 atoms per conventional cell
- Symmetry operations
- 16 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Mg2 | Mg | 4a | 4 | 0.0000 | 0.0000 | 0.2500 |
| Mg3 | Mg | 8f | 8 | 0.7600 | 0.0000 | 0.2500 |
| Ga1 | Ga | 8j | 8 | 0.6220 | 0.7550 | 0.0000 |
| Mg4 | Mg | 8j | 8 | 0.5770 | 0.1550 | 0.0000 |
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 28 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
A2B5_oI28_72_j_afj-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oI28, then the space-group number 72, then the Wyckoff letters occupied by each element in turn (Mg: 4a; Mg: 8f; Ga: 8j; Mg: 8j). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
As₂Cu₅, In₂Mg₅, Tl₂Mg₅, Mn₂Ge₅ <!--beginning with an
Note: D8_{g}.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B5_oI28_72_j_afj-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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