Crystal Lab › Prototype structures › Orthorhombic
β-SeO₂ O₂Se
Orthorhombic · space group Pmc21 (No. 26) · Pearson oP12
Symmetry elements and Wyckoff positions (interactive)
β-SeO₂ in Pmc21
SettingUnit cell
- Lattice constants
- a = 5.072 Å, b = 4.470 Å, c = 7.531 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 170.8 ų
- Atoms in the conventional cell
- 12 (O 8, Se 4)
- Formula units Z
- 4
- Pearson symbol
- oP12 — orthorhombic, primitive lattice, 12 atoms per conventional cell
- Symmetry operations
- 4 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| O1 | O | 2a | 2 | 0.0000 | 0.7460 | 0.6720 |
| Se4 | Se | 2a | 2 | 0.0000 | 0.1219 | 0.3748 |
| O2 | O | 2b | 2 | 0.5000 | 0.6200 | 0.9610 |
| Se5 | Se | 2b | 2 | 0.5000 | 0.2516 | 0.0000 |
| O3 | O | 4c | 4 | 0.2470 | 0.1520 | 0.8410 |
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 12 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
A2B_oP12_26_abc_ab-002: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP12, then the space-group number 26, then the Wyckoff letters occupied by each element in turn (O: 2a; Se: 2a; O: 2b; Se: 2b; O: 4c). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Note: \beta-SeO₂.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B_oP12_26_abc_ab-002 (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.
← H₂S 70 GPa · Space group Pmc21 (6 prototypes) · All prototypes · γ-SeO₂ — O₂Se →