Crystal Lab › Prototype structures › Orthorhombic
Hg₇Hg₅
Orthorhombic · space group Pbcm (No. 57) · Pearson oP48
Symmetry elements and Wyckoff positions (interactive)
Hg₇Hg₅ in Pbcm
SettingUnit cell
- Lattice constants
- a = 10.060 Å, b = 19.450 Å, c = 8.340 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 1631.9 ų
- Atoms in the conventional cell
- 48 (Hg 28, K 20)
- Formula units Z
- 4
- Pearson symbol
- oP48 — orthorhombic, primitive lattice, 48 atoms per conventional cell
- Symmetry operations
- 8 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Hg1 | Hg | 4c | 4 | 0.8701 | 0.2500 | 0.0000 |
| K5 | K | 4d | 4 | 0.5590 | 0.2200 | 0.2500 |
| K6 | K | 4d | 4 | 0.5380 | 0.0170 | 0.2500 |
| K7 | K | 4d | 4 | 0.1740 | 0.2100 | 0.2500 |
| K8 | K | 4d | 4 | 0.0090 | 0.3980 | 0.2500 |
| K9 | K | 4d | 4 | 0.8960 | 0.0830 | 0.2500 |
| Hg2 | Hg | 8e | 8 | 0.1994 | 0.0274 | 0.0646 |
| Hg3 | Hg | 8e | 8 | 0.6790 | 0.1194 | 0.5708 |
| Hg4 | Hg | 8e | 8 | 0.3737 | 0.1399 | 0.5708 |
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 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
A7B5_oP48_57_c3e_5d-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP48, then the space-group number 57, then the Wyckoff letters occupied by each element in turn (Hg: 4c; K: 4d; K: 4d; K: 4d; K: 4d; K: 4d; Hg: 8e; Hg: 8e; Hg: 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 A7B5_oP48_57_c3e_5d-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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