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Tetragonal Perovskite KCuF₃ CuF₃K

Tetragonal · space group I4/mcm (No. 140) · Pearson tI20

Symmetry elements and Wyckoff positions (interactive)

Tetragonal Perovskite KCuF₃ in I4/mcm

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

Unit cell

Lattice constants
a = 5.855 Å, b = 5.855 Å, c = 7.852 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
269.2 ų
Atoms in the conventional cell
20 (K 4, F 12, Cu 4)
Formula units Z
4
Pearson symbol
tI20 — tetragonal, body-centred lattice, 20 atoms per conventional cell
Symmetry operations
32 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
K4K4a40.00000.00000.2500
F2F4b40.00000.50000.2500
Cu1Cu4d40.00000.50000.0000
F3F8h80.22800.72800.0000

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 20 atoms drawn above are these sites multiplied by all 32 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

AB3C_tI20_140_d_bh_a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI20, then the space-group number 140, then the Wyckoff letters occupied by each element in turn (K: 4a; F: 4b; Cu: 4d; F: 8h). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

CsAgF₃, KCrF₃, RbCuF₃, RbAgF₃ <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB3C_tI20_140_d_bh_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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