Crystal Lab › Prototype structures › Orthorhombic
Selenic Acid (H₂SeO₃)
Orthorhombic · space group P212121 (No. 19) · Pearson oP28
Symmetry elements and Wyckoff positions (interactive)
Selenic Acid (H₂SeO₃) in P212121
SettingUnit cell
- Lattice constants
- a = 8.333 Å, b = 8.129 Å, c = 4.591 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 311.0 ų
- Atoms in the conventional cell
- 28 (H 8, O 16, Se 4)
- Formula units Z
- 4
- Pearson symbol
- oP28 — orthorhombic, primitive lattice, 28 atoms per conventional cell
- Symmetry operations
- 4 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| H1 | H | 4a | 4 | 0.4540 | 0.4790 | 0.5490 |
| H2 | H | 4a | 4 | 0.2220 | 0.1950 | 0.0200 |
| O3 | O | 4a | 4 | 0.5170 | 0.1310 | 0.7160 |
| O4 | O | 4a | 4 | 0.2890 | 0.1110 | 0.3050 |
| O5 | O | 4a | 4 | 0.2310 | 0.2660 | 0.8060 |
| O6 | O | 4a | 4 | 0.4130 | 0.3900 | 0.4100 |
| Se7 | Se | 4a | 4 | 0.3670 | 0.2090 | 0.5770 |
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 28 atoms drawn above are these sites multiplied by all 4 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
A2B4C_oP28_19_2a_4a_a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP28, then the space-group number 19, then the Wyckoff letters occupied by each element in turn (H: 4a; H: 4a; O: 4a; O: 4a; O: 4a; O: 4a; Se: 4a). 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 A2B4C_oP28_19_2a_4a_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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