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Crystal Lab › Prototype structures › Tetragonal

NaGdCu₂F₈

Tetragonal · space group I422 (No. 97) · Pearson tI24

Symmetry elements and Wyckoff positions (interactive)

NaGdCu₂F₈ in I422

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

Unit cell

Lattice constants
a = 5.407 Å, b = 5.407 Å, c = 10.382 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
303.5 ų
Atoms in the conventional cell
24 (Gd 2, Na 2, Cu 4, F 16)
Formula units Z
2
Pearson symbol
tI24 — tetragonal, body-centred lattice, 24 atoms per conventional cell
Symmetry operations
16 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Gd3Gd2a20.00000.00000.0000
Na4Na2b20.00000.00000.5000
Cu1Cu4d40.00000.50000.2500
F2F16k160.16970.31280.1237

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 24 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

A2B8CD_tI24_97_d_k_a_b-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI24, then the space-group number 97, then the Wyckoff letters occupied by each element in turn (Gd: 2a; Na: 2b; Cu: 4d; F: 16k). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B8CD_tI24_97_d_k_a_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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