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κ-AlF₃

Tetragonal · space group P4/mbm (No. 127) · Pearson tP40

Symmetry elements and Wyckoff positions (interactive)

κ-AlF₃ in P4/mbm

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

Unit cell

Lattice constants
a = 11.403 Å, b = 11.403 Å, c = 3.544 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
460.8 ų
Atoms in the conventional cell
40 (F 30, Al 10)
Formula units Z
10
Pearson symbol
tP40 — tetragonal, primitive lattice, 40 atoms per conventional cell
Symmetry operations
16 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
F3F2c20.00000.50000.5000
Al1Al2d20.00000.50000.0000
F4F4g40.21620.71620.0000
Al2Al8i80.42050.29280.0000
F5F8i80.35850.43330.0000
F6F8i80.50490.15680.0000
F7F8j80.42640.29500.5000

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 40 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

AB3_tP40_127_di_cg2ij-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tP40, then the space-group number 127, then the Wyckoff letters occupied by each element in turn (F: 2c; Al: 2d; F: 4g; Al: 8i; F: 8i; F: 8i; F: 8j). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Note: \kappa-AlF₃.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB3_tP40_127_di_cg2ij-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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