Crystal Lab › Prototype structures › Tetragonal
Ba₁₉Li₄₄
Tetragonal · space group I-42d (No. 122) · Pearson tI252
Symmetry elements and Wyckoff positions (interactive)
Ba₁₉Li₄₄ in I-42d
SettingUnit cell
- Lattice constants
- a = 16.391 Å, b = 16.391 Å, c = 32.712 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 8788.7 ų
- Atoms in the conventional cell
- 252 (Ba 76, Li 176)
- Formula units Z
- 4
- Pearson symbol
- tI252 — tetragonal, body-centred lattice, 252 atoms per conventional cell
- Symmetry operations
- 16 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Ba1 | Ba | 4a | 4 | 0.0000 | 0.0000 | 0.0000 |
| Ba2 | Ba | 8c | 8 | 0.0000 | 0.0000 | 0.5952 |
| Li7 | Li | 8d | 8 | 0.4903 | 0.2500 | 0.1250 |
| Li8 | Li | 8d | 8 | 0.9607 | 0.2500 | 0.1250 |
| Ba3 | Ba | 16e | 16 | 0.6119 | 0.5959 | 0.2020 |
| Ba4 | Ba | 16e | 16 | 0.9152 | 0.6000 | 0.0502 |
| Ba5 | Ba | 16e | 16 | 0.5043 | 0.8088 | 0.2510 |
| Ba6 | Ba | 16e | 16 | 0.8570 | 0.8493 | 0.0749 |
| Li10 | Li | 16e | 16 | 0.7815 | 0.0619 | 0.0321 |
| Li11 | Li | 16e | 16 | 0.7340 | 0.0191 | 0.1307 |
| Li12 | Li | 16e | 16 | 0.6346 | 0.6622 | 0.3152 |
| Li13 | Li | 16e | 16 | 0.0727 | 0.5626 | 0.1434 |
| Li14 | Li | 16e | 16 | 0.7435 | 0.7705 | 0.2586 |
| Li15 | Li | 16e | 16 | 0.6158 | 0.1376 | 0.0683 |
| Li16 | Li | 16e | 16 | 0.6511 | 0.1765 | 0.1609 |
| Li17 | Li | 16e | 16 | 0.7874 | 0.5752 | 0.2830 |
| Li18 | Li | 16e | 16 | 0.7850 | 0.1873 | 0.0945 |
| Li9 | Li | 16e | 16 | 0.6723 | 0.6708 | 0.0844 |
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 252 atoms drawn above are these sites multiplied by all 16 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
A19B44_tI252_122_ac4e_2d10e-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI252, then the space-group number 122, then the Wyckoff letters occupied by each element in turn (Ba: 4a; Ba: 8c; Li: 8d; Li: 8d; Ba: 16e; Ba: 16e; Ba: 16e; Ba: 16e; Li: 16e; Li: 16e; Li: 16e; Li: 16e; Li: 16e; Li: 16e; Li: 16e; Li: 16e; Li: 16e; Li: 16e). 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 A19B44_tI252_122_ac4e_2d10e-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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