Crystal Lab › Prototype structures › Orthorhombic
Orthorhombic La₃Ni₂O₇
Orthorhombic · space group Fmmm (No. 69) · Pearson oF48
Symmetry elements and Wyckoff positions (interactive)
Orthorhombic La₃Ni₂O₇ in Fmmm
SettingUnit cell
- Lattice constants
- a = 20.516 Å, b = 5.436 Å, c = 5.393 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 601.5 ų
- Atoms in the conventional cell
- 48 (La 12, O 28, Ni 8)
- Formula units Z
- 4
- Pearson symbol
- oF48 — orthorhombic, face-centred lattice, 48 atoms per conventional cell
- Symmetry operations
- 32 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| La1 | La | 4a | 4 | 0.0000 | 0.0000 | 0.0000 |
| O4 | O | 4b | 4 | 0.0000 | 0.0000 | 0.5000 |
| La2 | La | 8g | 8 | 0.8191 | 0.0000 | 0.0000 |
| Ni3 | Ni | 8g | 8 | 0.5975 | 0.0000 | 0.0000 |
| O5 | O | 8g | 8 | 0.6990 | 0.0000 | 0.0000 |
| O6 | O | 16l | 16 | 0.9005 | 0.2500 | 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 48 atoms drawn above are these sites multiplied by all 32 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
A3B2C7_oF48_69_ag_g_bgl-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oF48, then the space-group number 69, then the Wyckoff letters occupied by each element in turn (La: 4a; O: 4b; La: 8g; Ni: 8g; O: 8g; O: 16l). 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 A3B2C7_oF48_69_ag_g_bgl-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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