Crystal Lab › Prototype structures › Tetragonal
SrTb₂Fe₂O₇
Tetragonal · space group P42/mnm (No. 136) · Pearson tP48
Symmetry elements and Wyckoff positions (interactive)
SrTb₂Fe₂O₇ in P42/mnm
SettingUnit cell
- Lattice constants
- a = 5.506 Å, b = 5.506 Å, c = 19.659 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 596.1 ų
- Atoms in the conventional cell
- 48 (O 28, Sr 4, Fe 8, Tb 8)
- Formula units Z
- 4
- Pearson symbol
- tP48 — tetragonal, primitive lattice, 48 atoms per conventional cell
- Symmetry operations
- 16 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| O2 | O | 4e | 4 | 0.0000 | 0.0000 | 0.6080 |
| O3 | O | 4e | 4 | 0.0000 | 0.0000 | 0.9080 |
| O4 | O | 4f | 4 | 0.7840 | 0.7840 | 0.0000 |
| Sr7 | Sr | 4g | 4 | 0.2360 | 0.7640 | 0.0000 |
| O5 | O | 8h | 8 | 0.0000 | 0.5000 | 0.6260 |
| Fe1 | Fe | 8j | 8 | 0.2480 | 0.2480 | 0.9006 |
| O6 | O | 8j | 8 | 0.2070 | 0.2070 | 0.7850 |
| Tb8 | Tb | 8j | 8 | 0.2760 | 0.2760 | 0.6823 |
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 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
A2B7CD2_tP48_136_j_2efhj_g_j-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tP48, then the space-group number 136, then the Wyckoff letters occupied by each element in turn (O: 4e; O: 4e; O: 4f; Sr: 4g; O: 8h; Fe: 8j; O: 8j; Tb: 8j). 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 A2B7CD2_tP48_136_j_2efhj_g_j-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.
← Zr₃Al₂ · Space group P42/mnm (18 prototypes) · All prototypes · Rutile (TiO₂, C4) →