Crystal Lab › Prototype structures › Orthorhombic
Low Temperature SmBaMn₂O₆ BaMn₂O₆Sm
Orthorhombic · space group Pmc21 (No. 26) · Pearson oP40
Symmetry elements and Wyckoff positions (interactive)
Low Temperature SmBaMn₂O₆ in Pmc21
SettingUnit cell
- Lattice constants
- a = 7.581 Å, b = 5.543 Å, c = 11.096 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 466.3 ų
- Atoms in the conventional cell
- 40 (Ba 4, O 24, Sm 4, Mn 8)
- Formula units Z
- 4
- Pearson symbol
- oP40 — orthorhombic, primitive lattice, 40 atoms per conventional cell
- Symmetry operations
- 4 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Ba1 | Ba | 2a | 2 | 0.0000 | 0.0002 | 0.5165 |
| Ba2 | Ba | 2a | 2 | 0.0000 | 0.4906 | 0.7646 |
| O5 | O | 2a | 2 | 0.0000 | 0.5056 | 0.0052 |
| O6 | O | 2a | 2 | 0.0000 | 0.9971 | 0.7749 |
| O7 | O | 2b | 2 | 0.5000 | 0.9376 | 0.7407 |
| O8 | O | 2b | 2 | 0.5000 | 0.4815 | 0.0392 |
| Sm13 | Sm | 2b | 2 | 0.5000 | 0.4983 | 0.7609 |
| Sm14 | Sm | 2b | 2 | 0.5000 | 0.9968 | 0.5193 |
| Mn3 | Mn | 4c | 4 | 0.2565 | 0.9888 | 0.7659 |
| Mn4 | Mn | 4c | 4 | 0.2530 | 0.4988 | 0.0167 |
| O10 | O | 4c | 4 | 0.2448 | 0.7383 | 0.6437 |
| O11 | O | 4c | 4 | 0.2941 | 0.2249 | 0.8859 |
| O12 | O | 4c | 4 | 0.2686 | 0.2317 | 0.6481 |
| O9 | O | 4c | 4 | 0.2893 | 0.7379 | 0.8918 |
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 40 atoms drawn above are these sites multiplied by all 4 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
AB2C6D_oP40_26_2a_2c_2a2b4c_2b-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP40, then the space-group number 26, then the Wyckoff letters occupied by each element in turn (Ba: 2a; Ba: 2a; O: 2a; O: 2a; O: 2b; O: 2b; Sm: 2b; Sm: 2b; Mn: 4c; Mn: 4c; O: 4c; O: 4c; O: 4c; O: 4c). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Note: LT.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB2C6D_oP40_26_2a_2c_2a2b4c_2b-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.