Crystal Lab › Prototype structures › Orthorhombic
Ta₂S
Orthorhombic · space group Pbcm (No. 57) · Pearson oP36
Symmetry elements and Wyckoff positions (interactive)
Ta₂S in Pbcm
SettingUnit cell
- Lattice constants
- a = 7.379 Å, b = 5.574 Å, c = 15.190 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 624.8 ų
- Atoms in the conventional cell
- 36 (S 12, Ta 24)
- Formula units Z
- 12
- Pearson symbol
- oP36 — orthorhombic, primitive lattice, 36 atoms per conventional cell
- Symmetry operations
- 8 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| S1 | S | 4c | 4 | 0.1809 | 0.2500 | 0.0000 |
| Ta3 | Ta | 4d | 4 | 0.9910 | 0.6306 | 0.2500 |
| Ta4 | Ta | 4d | 4 | 0.3528 | 0.8709 | 0.2500 |
| S2 | S | 8e | 8 | 0.4132 | 0.7651 | 0.0955 |
| Ta5 | Ta | 8e | 8 | 0.0969 | 0.8930 | 0.0900 |
| Ta6 | Ta | 8e | 8 | 0.2841 | 0.3952 | 0.1541 |
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 36 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_oP36_57_ce_2d2e-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP36, then the space-group number 57, then the Wyckoff letters occupied by each element in turn (S: 4c; Ta: 4d; Ta: 4d; S: 8e; Ta: 8e; Ta: 8e). 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 AB2_oP36_57_ce_2d2e-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.
← Hg₇Hg₅ · Space group Pbcm (12 prototypes) · All prototypes · Coparsite [α-Cu₄O₂(VO₄)Cl] →