Crystal Lab › Prototype structures › Orthorhombic
BiGaO₃
Orthorhombic · space group Pcca (No. 54) · Pearson oP20
Symmetry elements and Wyckoff positions (interactive)
BiGaO₃ in Pcca
SettingUnit cell
- Lattice constants
- a = 5.347 Å, b = 5.115 Å, c = 9.716 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 265.7 ų
- Atoms in the conventional cell
- 20 (O 12, Ga 4, Bi 4)
- Formula units Z
- 4
- Pearson symbol
- oP20 — orthorhombic, primitive lattice, 20 atoms per conventional cell
- Symmetry operations
- 8 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| O3 | O | 4c | 4 | 0.0000 | 0.8667 | 0.2500 |
| Ga2 | Ga | 4d | 4 | 0.2500 | 0.0000 | 0.6417 |
| Bi1 | Bi | 4e | 4 | 0.2500 | 0.5000 | 0.8902 |
| O4 | O | 8f | 8 | 0.4055 | 0.2686 | 0.5503 |
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 8 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
ABC3_oP20_54_e_d_cf-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP20, then the space-group number 54, then the Wyckoff letters occupied by each element in turn (O: 4c; Ga: 4d; Bi: 4e; O: 8f). 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 ABC3_oP20_54_e_d_cf-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.