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α-Ni₇S₆

Orthorhombic · space group Cmcm (No. 63) · Pearson oC56

Symmetry elements and Wyckoff positions (interactive)

α-Ni₇S₆ in Cmcm

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

Unit cell

Lattice constants
a = 3.274 Å, b = 11.359 Å, c = 16.157 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
600.9 ų
Atoms in the conventional cell
56 (Ni 36, S 20)
Formula units Z
4
Pearson symbol
oC56 — orthorhombic, base-centred lattice, 56 atoms per conventional cell
Symmetry operations
16 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Ni1Ni4c40.00000.84480.2500
S6S4c40.00000.64180.2500
Ni2Ni8f80.00000.28380.6277
Ni3Ni8f80.00000.96010.6728
Ni4Ni8f80.00000.68360.5289
Ni5Ni8f80.00000.51950.5346
S7S8f80.00000.87930.5450
S8S8f80.00000.61420.6527

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 56 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

A9B5_oC56_63_c4f_c2f-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oC56, then the space-group number 63, then the Wyckoff letters occupied by each element in turn (Ni: 4c; S: 4c; Ni: 8f; Ni: 8f; Ni: 8f; Ni: 8f; S: 8f; S: 8f). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Note: α-Ni₇S₆.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A9B5_oC56_63_c4f_c2f-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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