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Crystal Lab › Prototype structures › Tetragonal

Sr₂CuO₂Cl₂

Tetragonal · space group I4/mmm (No. 139) · Pearson tI14

Symmetry elements and Wyckoff positions (interactive)

Sr₂CuO₂Cl₂ in I4/mmm

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

Unit cell

Lattice constants
a = 3.972 Å, b = 3.972 Å, c = 15.613 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
246.3 ų
Atoms in the conventional cell
14 (Cu 2, O 4, Cl 4, Sr 4)
Formula units Z
2
Pearson symbol
tI14 — tetragonal, body-centred lattice, 14 atoms per conventional cell
Symmetry operations
32 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Cu2Cu2a20.00000.00000.0000
O3O4c40.00000.50000.0000
Cl1Cl4e40.00000.00000.1831
Sr4Sr4e40.00000.00000.3926

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 14 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

A2BC2D2_tI14_139_e_a_c_e-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI14, then the space-group number 139, then the Wyckoff letters occupied by each element in turn (Cu: 2a; O: 4c; Cl: 4e; Sr: 4e). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Ca₂CuO₂Cl₂, Na₂Fe₂Se₂O, Na₂Ti₂As₂O, Na₂Ti₂Sb₂O <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2BC2D2_tI14_139_e_a_c_e-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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