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Crystal Lab › Prototype structures › Tetragonal

Tl₂CdGeTe₄

Tetragonal · space group I-42m (No. 121) · Pearson tI16

Symmetry elements and Wyckoff positions (interactive)

Tl₂CdGeTe₄ in I-42m

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

Unit cell

Lattice constants
a = 8.383 Å, b = 8.383 Å, c = 7.077 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
497.3 ų
Atoms in the conventional cell
16 (Cd 2, Ge 2, Tl 4, Te 8)
Formula units Z
2
Pearson symbol
tI16 — tetragonal, body-centred lattice, 16 atoms per conventional cell
Symmetry operations
16 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Cd1Cd2a20.00000.00000.0000
Ge2Ge2b20.00000.00000.5000
Tl4Tl4c40.00000.50000.0000
Te3Te8i80.17490.17490.2748

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 16 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

ABC4D2_tI16_121_a_b_i_c-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI16, then the space-group number 121, then the Wyckoff letters occupied by each element in turn (Cd: 2a; Ge: 2b; Tl: 4c; Te: 8i). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Tl₂CdSnTe₄, Tl₂HgGeTe₄, Tl₂HgSiSe₄, Tl₂HgSnSe₄, Tl₂HgSnTe₄, Tl₂MnGeTe₄, Tl₂MnSnTe₄ <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry ABC4D2_tI16_121_a_b_i_c-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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