Crystal Lab › Prototype structures › Orthorhombic
η-Fe₂C
Orthorhombic · space group Pnnm (No. 58) · Pearson oP6
Symmetry elements and Wyckoff positions (interactive)
η-Fe₂C in Pnnm
SettingUnit cell
- Lattice constants
- a = 4.704 Å, b = 4.318 Å, c = 2.830 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 57.5 ų
- Atoms in the conventional cell
- 6 (C 2, Fe 4)
- Formula units Z
- 2
- Pearson symbol
- oP6 — orthorhombic, primitive lattice, 6 atoms per conventional cell
- Symmetry operations
- 8 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| C1 | C | 2a | 2 | 0.0000 | 0.0000 | 0.0000 |
| Fe2 | Fe | 4g | 4 | 0.6667 | 0.2500 | 0.0000 |
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 6 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
AB2_oP6_58_a_g-002: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP6, then the space-group number 58, then the Wyckoff letters occupied by each element in turn (C: 2a; Fe: 4g). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
C₂Si, Co₂C, Co₂N, N₂Al, N₂Os, Pd₂B, Pd₂N, Rh₂C <!--beginning with an
Note: \eta-Fe₂C.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB2_oP6_58_a_g-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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