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Crystal Lab › Prototype structures › Tetragonal

Sm₂NiGa₁₂

Tetragonal · space group P4/nbm (No. 125) · Pearson tP30

Symmetry elements and Wyckoff positions (interactive)

Sm₂NiGa₁₂ in P4/nbm

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

Unit cell

Lattice constants
a = 5.995 Å, b = 5.995 Å, c = 15.401 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
553.6 ų
Atoms in the conventional cell
30 (Ni 2, Ga 24, Sm 4)
Formula units Z
2
Pearson symbol
tP30 — tetragonal, primitive lattice, 30 atoms per conventional cell
Symmetry operations
16 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Ni5Ni2c20.75000.25000.0000
Ga1Ga4g40.25000.25000.1811
Ga2Ga4g40.25000.25000.3394
Sm6Sm4h40.75000.25000.2450
Ga3Ga8m80.57040.42960.0833
Ga4Ga8m80.57200.42800.5721

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 30 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

A12BC2_tP30_125_2g2m_c_h-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tP30, then the space-group number 125, then the Wyckoff letters occupied by each element in turn (Ni: 2c; Ga: 4g; Ga: 4g; Sm: 4h; Ga: 8m; Ga: 8m). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Ce₂CuGa₁₂, Ce₂IrGa₁₂, Ce₂NiGa₁₂, Ce₂PdGa₁₂, La₂CuGa₁₂, La₂NiGa₁₂, La₂PdGa₁₂, Nd₂CuGa₁₂, Nd₂NiGa₁₂, Nd₂PdGa₁₂, Pr₂CuGa₁₂, Pr₂NiGa₁₂, Pr₂PdGa₁₂, Sm₂CuGa₁₂, Sm₂PdGa₁₂ <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A12BC2_tP30_125_2g2m_c_h-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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