Crystal Lab › Prototype structures › Tetragonal
Mn₄Ge₇ Nowotny Chimney-Ladder Mn₄Si₇
Tetragonal · space group P-4c2 (No. 116) · Pearson tP44
Symmetry elements and Wyckoff positions (interactive)
Mn₄Ge₇ Nowotny Chimney-Ladder in P-4c2
SettingUnit cell
- Lattice constants
- a = 5.525 Å, b = 5.525 Å, c = 17.463 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 533.1 ų
- Atoms in the conventional cell
- 44 (Mn 16, Si 28)
- Formula units Z
- 4
- Pearson symbol
- tP44 — tetragonal, primitive lattice, 44 atoms per conventional cell
- Symmetry operations
- 8 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Mn1 | Mn | 2a | 2 | 0.0000 | 0.0000 | 0.2500 |
| Mn2 | Mn | 2c | 2 | 0.0000 | 0.0000 | 0.0000 |
| Si6 | Si | 4e | 4 | 0.3333 | 0.3333 | 0.2500 |
| Mn3 | Mn | 4h | 4 | 0.5000 | 0.5000 | 0.1250 |
| Mn4 | Mn | 4i | 4 | 0.0000 | 0.5000 | 0.0625 |
| Mn5 | Mn | 4i | 4 | 0.0000 | 0.5000 | 0.3125 |
| Si7 | Si | 8j | 8 | 0.3436 | 0.7721 | 0.0409 |
| Si8 | Si | 8j | 8 | 0.1933 | 0.1507 | 0.1129 |
| Si9 | Si | 8j | 8 | 0.1627 | 0.6791 | 0.1815 |
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 44 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
A4B7_tP44_116_ach2i_e3j-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tP44, then the space-group number 116, then the Wyckoff letters occupied by each element in turn (Mn: 2a; Mn: 2c; Si: 4e; Mn: 4h; Mn: 4i; Mn: 4i; Si: 8j; Si: 8j; Si: 8j). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Note: Nowotny Chimney-Ladder.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A4B7_tP44_116_ach2i_e3j-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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