Crystal Lab › Prototype structures › Monoclinic
α-Bi₂O₃
Monoclinic · space group P121/c1 (No. 14) · Pearson mP20
Symmetry elements and Wyckoff positions (interactive)
α-Bi₂O₃ in P121/c1
SettingUnit cell
- Lattice constants
- a = 5.850 Å, b = 8.165 Å, c = 7.510 Å; α = 90.00°, β = 112.98°, γ = 90.00°
- Cell volume
- 330.2 ų
- Atoms in the conventional cell
- 20 (Bi 8, O 12)
- Formula units Z
- 4
- Pearson symbol
- mP20 — monoclinic, primitive lattice, 20 atoms per conventional cell
- Symmetry operations
- 4 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Bi1 | Bi | 4e | 4 | 0.5242 | 0.1843 | 0.3615 |
| Bi2 | Bi | 4e | 4 | 0.0404 | 0.0425 | 0.7767 |
| O3 | O | 4e | 4 | 0.7783 | 0.3037 | 0.7080 |
| O4 | O | 4e | 4 | 0.2337 | 0.0467 | 0.1266 |
| O5 | O | 4e | 4 | 0.2658 | 0.0294 | 0.5115 |
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 20 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
A2B3_mP20_14_2e_3e-003: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol mP20, then the space-group number 14, then the Wyckoff letters occupied by each element in turn (Bi: 4e; Bi: 4e; O: 4e; O: 4e; O: 4e). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Note: α-Bi₂O₃.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B3_mP20_14_2e_3e-003 (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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