Crystal Lab › Prototype structures › Orthorhombic
NaCu₂O₂
Orthorhombic · space group Pnma (No. 62) · Pearson oP20
Symmetry elements and Wyckoff positions (interactive)
NaCu₂O₂ in Pnma
SettingUnit cell
- Lattice constants
- a = 6.200 Å, b = 2.931 Å, c = 13.034 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 236.9 ų
- Atoms in the conventional cell
- 20 (Cu 8, Na 4, O 8)
- 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 |
|---|---|---|---|---|---|---|
| Cu1 | Cu | 4c | 4 | 0.3810 | 0.2500 | 0.2549 |
| Cu2 | Cu | 4c | 4 | 0.8694 | 0.2500 | 0.6059 |
| Na3 | Na | 4c | 4 | 0.3580 | 0.2500 | 0.5806 |
| O4 | O | 4c | 4 | 0.4189 | 0.2500 | 0.1155 |
| O5 | O | 4c | 4 | 0.3489 | 0.2500 | 0.3979 |
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
A2BC2_oP20_62_2c_c_2c-002: 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 62, then the Wyckoff letters occupied by each element in turn (Cu: 4c; Cu: 4c; Na: 4c; O: 4c; O: 4c). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
LiCu₂O₂ <!--beginning with an
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2BC2_oP20_62_2c_c_2c-002 (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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