Crystal Lab › Prototype structures › Tetragonal
SrCu₂(BO₃)₂
Tetragonal · space group I-42m (No. 121) · Pearson tI44
Symmetry elements and Wyckoff positions (interactive)
SrCu₂(BO₃)₂ in I-42m
SettingUnit cell
- Lattice constants
- a = 8.995 Å, b = 8.995 Å, c = 6.649 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 538.0 ų
- Atoms in the conventional cell
- 44 (Sr 4, B 8, Cu 8, O 24)
- Formula units Z
- 4
- Pearson symbol
- tI44 — tetragonal, body-centred lattice, 44 atoms per conventional cell
- Symmetry operations
- 16 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Sr5 | Sr | 4c | 4 | 0.0000 | 0.5000 | 0.0000 |
| B1 | B | 8i | 8 | 0.2953 | 0.2953 | 0.2430 |
| Cu2 | Cu | 8i | 8 | 0.1141 | 0.1141 | 0.2783 |
| O3 | O | 8i | 8 | 0.4004 | 0.4004 | 0.2120 |
| O4 | O | 16j | 16 | 0.3276 | 0.1456 | 0.2540 |
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 44 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
A2B2C6D_tI44_121_i_i_ij_c-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI44, then the space-group number 121, then the Wyckoff letters occupied by each element in turn (Sr: 4c; B: 8i; Cu: 8i; O: 8i; O: 16j). 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 A2B2C6D_tI44_121_i_i_ij_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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