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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

Setting
Loading the group…
x = 0.10, y = 0.17, z = 0.08

Unit 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

SiteElementWyckoffMultiplicityxyz
Cu1Cu16e160.49820.12500.1250
Mg3Mg16e160.04150.12500.1250
Mg2Mg16f160.12500.79140.1250

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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