Crystal Lab › Prototype structures › Orthorhombic
Koechlinite (Room temperature Bi₂MoO₆)
Orthorhombic · space group Pca21 (No. 29) · Pearson oP36 · mineral: koechlinite
Symmetry elements and Wyckoff positions (interactive)
Koechlinite (Room temperature Bi₂MoO₆) in Pca21
SettingUnit cell
- Lattice constants
- a = 5.482 Å, b = 16.199 Å, c = 5.509 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 489.2 ų
- Atoms in the conventional cell
- 36 (Bi 8, Mo 4, O 24)
- Formula units Z
- 4
- Pearson symbol
- oP36 — orthorhombic, primitive lattice, 36 atoms per conventional cell
- Symmetry operations
- 4 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Bi1 | Bi | 4a | 4 | 0.5180 | 0.4232 | 0.9814 |
| Bi2 | Bi | 4a | 4 | 0.4822 | 0.0783 | 0.9897 |
| Mo3 | Mo | 4a | 4 | 0.0028 | 0.2488 | 0.0000 |
| O4 | O | 4a | 4 | 0.0556 | 0.1407 | 0.0959 |
| O5 | O | 4a | 4 | 0.2594 | 0.9983 | 0.2776 |
| O6 | O | 4a | 4 | 0.2360 | 0.5006 | 0.2664 |
| O7 | O | 4a | 4 | 0.6917 | 0.2322 | 0.2524 |
| O8 | O | 4a | 4 | 0.2121 | 0.2634 | 0.3550 |
| O9 | O | 4a | 4 | 0.5654 | 0.3589 | 0.5700 |
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 36 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
A2BC6_oP36_29_2a_a_6a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP36, then the space-group number 29, then the Wyckoff letters occupied by each element in turn (Bi: 4a; Bi: 4a; Mo: 4a; O: 4a; O: 4a; O: 4a; O: 4a; O: 4a; O: 4a). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
Bi₂WO₆ (russelite) <!--beginning with an
Note: Koechlinite (RT).
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2BC6_oP36_29_2a_a_6a-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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