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Crystal Lab › Prototype structures › Hexagonal

Mg₂Ni (C_{a})

Hexagonal · space group P6222 (No. 180) · Pearson hP18 · Strukturbericht Ca

Symmetry elements and Wyckoff positions (interactive)

Mg₂Ni (C_{a}) in P6222

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

Unit cell

Lattice constants
a = 5.198 Å, b = 5.198 Å, c = 13.210 Å; α = 90.00°, β = 90.00°, γ = 120.00°
Cell volume
309.1 ų
Atoms in the conventional cell
18 (Ni 6, Mg 12)
Formula units Z
6
Pearson symbol
hP18 — hexagonal / trigonal, primitive lattice, 18 atoms per conventional cell
Symmetry operations
12 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Ni3Ni3a30.00000.00000.0000
Ni4Ni3c30.50000.00000.0000
Mg1Mg6f60.50000.00000.6149
Mg2Mg6j60.16350.32700.5000

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 18 atoms drawn above are these sites multiplied by all 12 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_hP18_180_fj_ac-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hP18, then the space-group number 180, then the Wyckoff letters occupied by each element in turn (Ni: 3a; Ni: 3c; Mg: 6f; Mg: 6j). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

CuMg₄Ni, MoSn₂ <!--beginning with an

Note: C_{a}.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B_hP18_180_fj_ac-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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