Crystal Lab › Prototype structures › Tetragonal
Sr(OH)₂(H₂O)₈
Tetragonal · space group P4/ncc (No. 130) · Pearson tP116
Symmetry elements and Wyckoff positions (interactive)
Sr(OH)₂(H₂O)₈ in P4/ncc
SettingUnit cell
- Lattice constants
- a = 8.984 Å, b = 8.984 Å, c = 11.517 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 929.6 ų
- Atoms in the conventional cell
- 116 (Sr 4, H 72, O 40)
- Formula units Z
- 4
- Pearson symbol
- tP116 — tetragonal, primitive lattice, 116 atoms per conventional cell
- Symmetry operations
- 16 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Sr11 | Sr | 4a | 4 | 0.7500 | 0.2500 | 0.2500 |
| H1 | H | 4c | 4 | 0.2500 | 0.2500 | 0.4888 |
| H2 | H | 4c | 4 | 0.2500 | 0.2500 | 0.2426 |
| O7 | O | 4c | 4 | 0.2500 | 0.2500 | 0.4048 |
| O8 | O | 4c | 4 | 0.2500 | 0.2500 | 0.1590 |
| H3 | H | 16g | 16 | 0.8044 | 0.5759 | 0.1201 |
| H4 | H | 16g | 16 | 0.9530 | 0.4874 | 0.1327 |
| H5 | H | 16g | 16 | 0.8054 | 0.5766 | 0.8623 |
| H6 | H | 16g | 16 | 0.8392 | 0.4596 | 0.9602 |
| O9 | O | 16g | 16 | 0.8454 | 0.4722 | 0.1255 |
| O10 | O | 16g | 16 | 0.8459 | 0.4737 | 0.8766 |
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 116 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
A18B10C_tP116_130_2c4g_2c2g_a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tP116, then the space-group number 130, then the Wyckoff letters occupied by each element in turn (Sr: 4a; H: 4c; H: 4c; O: 4c; O: 4c; H: 16g; H: 16g; H: 16g; H: 16g; O: 16g; O: 16g). 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 A18B10C_tP116_130_2c4g_2c2g_a-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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