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High Temperature Cu₂Se

Cubic · space group Fm-3m (No. 225) · Pearson cF76

Symmetry elements and Wyckoff positions (interactive)

High Temperature Cu₂Se in Fm-3m

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

Unit cell

Lattice constants
a = 5.859 Å, b = 5.859 Å, c = 5.859 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
201.1 ų
Atoms in the conventional cell
76 (Se 4, Cu 72)
Formula units Z
4
Pearson symbol
cF76 — cubic, face-centred lattice, 76 atoms per conventional cell
Symmetry operations
192 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Se4Se4a40.00000.00000.0000
Cu1Cu8c80.25000.25000.2500
Cu2Cu32f320.30900.30900.3090
Cu3Cu32f320.38400.38400.3840

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 76 atoms drawn above are these sites multiplied by all 192 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

A18B_cF76_225_c2f_a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol cF76, then the space-group number 225, then the Wyckoff letters occupied by each element in turn (Se: 4a; Cu: 8c; Cu: 32f; Cu: 32f). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Ag₂Te (HT), Cu_{1.8}S <!--beginning with an

Note: HT.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A18B_cF76_225_c2f_a-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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