Crystal Lab › Prototype structures › Orthorhombic
Kotoite (Mg₃(BO₃)₂)
Orthorhombic · space group Pnnm (No. 58) · Pearson oP22 · mineral: kotoite
Symmetry elements and Wyckoff positions (interactive)
Kotoite (Mg₃(BO₃)₂) in Pnnm
SettingUnit cell
- Lattice constants
- a = 4.497 Å, b = 5.398 Å, c = 8.416 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 204.3 ų
- Atoms in the conventional cell
- 22 (Mg 6, B 4, O 12)
- Formula units Z
- 2
- Pearson symbol
- oP22 — orthorhombic, primitive lattice, 22 atoms per conventional cell
- Symmetry operations
- 8 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Mg2 | Mg | 2a | 2 | 0.0000 | 0.0000 | 0.0000 |
| Mg3 | Mg | 4f | 4 | 0.0000 | 0.5000 | 0.1790 |
| B1 | B | 4g | 4 | 0.5600 | 0.2500 | 0.0000 |
| O4 | O | 4g | 4 | 0.2580 | 0.3160 | 0.0000 |
| O5 | O | 8h | 8 | 0.7050 | 0.2180 | 0.1390 |
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 22 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
A2B3C6_oP22_58_g_af_gh-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP22, then the space-group number 58, then the Wyckoff letters occupied by each element in turn (Mg: 2a; Mg: 4f; B: 4g; O: 4g; O: 8h). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
Co₃(BO₃)₂, Ni₃(BO₃)₂, Mn₃(BO₃)₂ (jimboite), CoNi₂(BO₃)₂, KNa₂(BO₃)₂, Eu₃(BO₃)₂ <!--beginning with an
Note: Kotoite.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B3C6_oP22_58_g_af_gh-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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