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Predicted Li₂MgH₁₆ High-T_{c} Superconductor (250 GPa)

Cubic · space group Fd-3m (No. 227) · Pearson cF152

Symmetry elements and Wyckoff positions (interactive)

Predicted Li₂MgH₁₆ High-T_{c} Superconductor (250 GPa) in Fd-3m

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

Unit cell

Lattice constants
a = 6.718 Å, b = 6.718 Å, c = 6.718 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
303.3 ų
Atoms in the conventional cell
152 (Mg 8, Li 16, H 128)
Formula units Z
8
Pearson symbol
cF152 — cubic, face-centred lattice, 152 atoms per conventional cell
Symmetry operations
192 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Mg4Mg8b80.37500.37500.3750
Li3Li16c160.00000.00000.0000
H1H32e320.79150.79150.7915
H2H96g960.56030.56030.3706

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 152 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

A16B2C_cF152_227_eg_c_b-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol cF152, then the space-group number 227, then the Wyckoff letters occupied by each element in turn (Mg: 8b; Li: 16c; H: 32e; H: 96g). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Note: Predicted, 250 GPa.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A16B2C_cF152_227_eg_c_b-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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