Crystal Lab › Prototype structures › Orthorhombic
β-SrRh₂As₂ As₂Rh₂Sr
Orthorhombic · space group Fmmm (No. 69) · Pearson oF20
Symmetry elements and Wyckoff positions (interactive)
β-SrRh₂As₂ in Fmmm
SettingUnit cell
- Lattice constants
- a = 11.144 Å, b = 5.744 Å, c = 6.115 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 391.4 ų
- Atoms in the conventional cell
- 20 (Sr 4, Rh 8, As 8)
- Formula units Z
- 4
- Pearson symbol
- oF20 — orthorhombic, face-centred lattice, 20 atoms per conventional cell
- Symmetry operations
- 32 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Sr3 | Sr | 4a | 4 | 0.0000 | 0.0000 | 0.0000 |
| Rh2 | Rh | 8f | 8 | 0.2500 | 0.2500 | 0.2500 |
| As1 | As | 8g | 8 | 0.6410 | 0.0000 | 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 20 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
A2B2C_oF20_69_g_f_a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oF20, then the space-group number 69, then the Wyckoff letters occupied by each element in turn (Sr: 4a; Rh: 8f; As: 8g). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
EuRh₂As₂ <!--beginning with an
Note: \beta-SrRh₂As₂.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B2C_oF20_69_g_f_a-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.
· Space group Fmmm (10 prototypes) · All prototypes · SrLa₂Sc₂O₇ →