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Si₃₄ Clathrate

Cubic · space group Fd-3m (No. 227) · Pearson cF136

Symmetry elements and Wyckoff positions (interactive)

Si₃₄ Clathrate in Fd-3m

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

Unit cell

Lattice constants
a = 14.864 Å, b = 14.864 Å, c = 14.864 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
3284.0 ų
Atoms in the conventional cell
136 (Si 136)
Formula units Z
136
Pearson symbol
cF136 — cubic, face-centred lattice, 136 atoms per conventional cell
Symmetry operations
192 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Si1Si8a80.12500.12500.1250
Si2Si32e320.26240.26240.2624
Si3Si96g960.18240.18240.3701

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 136 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

A_cF136_227_aeg-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol cF136, then the space-group number 227, then the Wyckoff letters occupied by each element in turn (Si: 8a; Si: 32e; Si: 96g). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Ge (high pressure) <!--beginning with an

Note: Clathrate.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A_cF136_227_aeg-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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