Crystal Lab › Prototype structures › Orthorhombic
Mn₃As (D0_{d})
Orthorhombic · space group Cmcm (No. 63) · Pearson oC16
Symmetry elements and Wyckoff positions (interactive)
Mn₃As (D0_{d}) in Cmcm
SettingUnit cell
- Lattice constants
- a = 3.788 Å, b = 16.250 Å, c = 3.788 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 233.1 ų
- Atoms in the conventional cell
- 16 (As 4, Mn 12)
- Formula units Z
- 4
- Pearson symbol
- oC16 — orthorhombic, base-centred lattice, 16 atoms per conventional cell
- Symmetry operations
- 16 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| As1 | As | 4c | 4 | 0.0000 | 0.1590 | 0.2500 |
| Mn2 | Mn | 4c | 4 | 0.0000 | 0.9435 | 0.2500 |
| Mn3 | Mn | 4c | 4 | 0.0000 | 0.5565 | 0.2500 |
| Mn4 | Mn | 4c | 4 | 0.0000 | 0.3155 | 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 16 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_63_c_3c-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 63, then the Wyckoff letters occupied by each element in turn (As: 4c; Mn: 4c; Mn: 4c; Mn: 4c). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
Te₃Nd, DyGe₃ <!--beginning with an
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB3_oC16_63_c_3c-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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