Crystal Lab › Prototype structures › Orthorhombic
D0₇ (CrO₃) Structure ( Obsolete ): AB3_oC16_20_a_bc-001
Orthorhombic · space group C2221 (No. 20) · Pearson oC16 · Strukturbericht D07
Symmetry elements and Wyckoff positions (interactive)
D0₇ (CrO₃) Structure ( Obsolete ): AB3_oC16_20_a_bc-001 in C2221
SettingUnit cell
- Lattice constants
- a = 8.460 Å, b = 4.770 Å, c = 5.700 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 230.0 ų
- Atoms in the conventional cell
- 16 (Cr 4, O 12)
- Formula units Z
- 4
- Pearson symbol
- oC16 — orthorhombic, base-centred lattice, 16 atoms per conventional cell
- Symmetry operations
- 8 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Cr1 | Cr | 4a | 4 | 0.3333 | 0.0000 | 0.0000 |
| O2 | O | 4b | 4 | 0.0000 | 0.3333 | 0.2500 |
| O3 | O | 8c | 8 | 0.1667 | 0.8333 | 0.2500 |
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 16 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
AB3_oC16_20_a_bc-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oC16, then the space-group number 20, then the Wyckoff letters occupied by each element in turn (Cr: 4a; O: 4b; O: 8c). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Note: D0₇, (Obsolete).
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB3_oC16_20_a_bc-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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