Crystal Lab › Prototype structures › Orthorhombic
Godlevskite (Ni₉S₈)
Orthorhombic · space group C222 (No. 21) · Pearson oC68 · mineral: godlevskite
Symmetry elements and Wyckoff positions (interactive)
Godlevskite (Ni₉S₈) in C222
SettingUnit cell
- Lattice constants
- a = 11.219 Å, b = 9.336 Å, c = 9.430 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 987.6 ų
- Atoms in the conventional cell
- 68 (Ni 36, S 32)
- Formula units Z
- 4
- Pearson symbol
- oC68 — orthorhombic, base-centred lattice, 68 atoms per conventional cell
- Symmetry operations
- 8 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Ni1 | Ni | 2a | 2 | 0.0000 | 0.0000 | 0.0000 |
| Ni2 | Ni | 2c | 2 | 0.5000 | 0.0000 | 0.5000 |
| Ni3 | Ni | 4e | 4 | 0.2365 | 0.0000 | 0.0000 |
| Ni4 | Ni | 4h | 4 | 0.0000 | 0.2201 | 0.5000 |
| Ni5 | Ni | 4i | 4 | 0.0000 | 0.0000 | 0.7152 |
| Ni6 | Ni | 4k | 4 | 0.2500 | 0.2500 | 0.7719 |
| Ni7 | Ni | 8l | 8 | 0.6841 | 0.3737 | 0.6214 |
| Ni8 | Ni | 8l | 8 | 0.0878 | 0.6257 | 0.8737 |
| S10 | S | 8l | 8 | 0.1169 | 0.8672 | 0.8616 |
| S11 | S | 8l | 8 | 0.3483 | 0.3821 | 0.6198 |
| S12 | S | 8l | 8 | 0.8802 | 0.6198 | 0.8859 |
| S9 | S | 8l | 8 | 0.1161 | 0.6327 | 0.6348 |
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 68 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
A9B8_oC68_21_acehik2l_4l-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oC68, then the space-group number 21, then the Wyckoff letters occupied by each element in turn (Ni: 2a; Ni: 2c; Ni: 4e; Ni: 4h; Ni: 4i; Ni: 4k; Ni: 8l; Ni: 8l; S: 8l; S: 8l; S: 8l; S: 8l). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Note: Godlevskite.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A9B8_oC68_21_acehik2l_4l-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.