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
SettingUnit 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
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Cu2 | Cu | 2a | 2 | 0.0000 | 0.0000 | 0.0000 |
| O3 | O | 4c | 4 | 0.0000 | 0.5000 | 0.0000 |
| Cl1 | Cl | 4e | 4 | 0.0000 | 0.0000 | 0.1831 |
| Sr4 | Sr | 4e | 4 | 0.0000 | 0.0000 | 0.3926 |
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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