Crystal Lab › Prototype structures › Orthorhombic
Seligmannite (PbCuAsS₃)
Orthorhombic · space group Pmn21 (No. 31) · Pearson oP24 · mineral: seligmannite
Symmetry elements and Wyckoff positions (interactive)
Seligmannite (PbCuAsS₃) in Pmn21
SettingUnit cell
- Lattice constants
- a = 7.634 Å, b = 8.076 Å, c = 8.737 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 538.7 ų
- Atoms in the conventional cell
- 24 (As 4, Pb 4, S 12, Cu 4)
- Formula units Z
- 4
- Pearson symbol
- oP24 — orthorhombic, primitive lattice, 24 atoms per conventional cell
- Symmetry operations
- 4 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| As1 | As | 2a | 2 | 0.0000 | 0.9368 | 0.5736 |
| As2 | As | 2a | 2 | 0.0000 | 0.4959 | 0.1574 |
| Pb4 | Pb | 2a | 2 | 0.0000 | 0.0790 | 0.0061 |
| Pb5 | Pb | 2a | 2 | 0.0000 | 0.4463 | 0.6927 |
| S6 | S | 2a | 2 | 0.0000 | 0.2485 | 0.2791 |
| S7 | S | 2a | 2 | 0.0000 | 0.7780 | 0.7924 |
| Cu3 | Cu | 4b | 4 | 0.2411 | 0.2743 | 0.4276 |
| S8 | S | 4b | 4 | 0.2293 | 0.1042 | 0.6434 |
| S9 | S | 4b | 4 | 0.2753 | 0.5587 | 0.4940 |
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 24 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
ABCD3_oP24_31_2a_b_2a_2a2b-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP24, then the space-group number 31, then the Wyckoff letters occupied by each element in turn (As: 2a; As: 2a; Pb: 2a; Pb: 2a; S: 2a; S: 2a; Cu: 4b; S: 4b; S: 4b). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
PbCuSbS₃ (bournonite) <!--beginning with an
Note: Seligmannite.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry ABCD3_oP24_31_2a_b_2a_2a2b-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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