Crystal Lab › Prototype structures › Tetragonal
BeSO₄cdot4H₂O (H4₃)
Tetragonal · space group I-4c2 (No. 120) · Pearson tI72 · Strukturbericht H43
Symmetry elements and Wyckoff positions (interactive)
BeSO₄cdot4H₂O (H4₃) in I-4c2
SettingUnit cell
- Lattice constants
- a = 7.990 Å, b = 7.990 Å, c = 10.688 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 682.3 ų
- Atoms in the conventional cell
- 72 (Be 4, S 4, H 32, O 32)
- Formula units Z
- 4
- Pearson symbol
- tI72 — tetragonal, body-centred lattice, 72 atoms per conventional cell
- Symmetry operations
- 16 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Be1 | Be | 4b | 4 | 0.0000 | 0.0000 | 0.0000 |
| S6 | S | 4c | 4 | 0.0000 | 0.5000 | 0.2500 |
| H2 | H | 16i | 16 | 0.2273 | 0.4570 | 0.1311 |
| H3 | H | 16i | 16 | 0.1229 | 0.2842 | 0.1363 |
| O4 | O | 16i | 16 | 0.1256 | 0.0841 | 0.0773 |
| O5 | O | 16i | 16 | 0.1376 | 0.3956 | 0.1709 |
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 72 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
AB8C8D_tI72_120_b_2i_2i_c-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI72, then the space-group number 120, then the Wyckoff letters occupied by each element in turn (Be: 4b; S: 4c; H: 16i; H: 16i; O: 16i; O: 16i). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Note: H4₃.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB8C8D_tI72_120_b_2i_2i_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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