Crystal Lab › AB₂ and A₂B
Lithium bismuthide Li₃Bi
A₃B (BiF₃ / Li₃Bi type) · space group Fm-3m (No. 225) · Z = 4
Symmetry elements and Wyckoff positions (interactive)
Lithium bismuthide in Fm-3m
SettingLoading the group…
x = 0.10, y = 0.17, z = 0.08
Unit cell
- Lattice constants
- a = 6.722 Å, b = 6.722 Å, c = 6.722 Å; α = 90°, β = 90°, γ = 90°
- Cell volume
- 303.7 ų
- Atoms in the cell
- 16 (Bi 4, Li 12)
- Formula units Z
- 4
- Calculated density
- 5.03 g cm⁻³
- Shortest contact
- 2.911 Å
Coordination
- Bi
- CN 8 at 2.91 Å (8 Li)
- Li
- CN 5 at 3.36 Å (4.67 Bi)
About the structure
- A ccp array of Bi with Li in every octahedral hole (4b) and every tetrahedral hole (8c): rock salt plus fluorite filling at once, so A₃B — the anti-form of BiF₃ and the structure of Fe₃Al.
- A textbook example for counting holes in ccp: 4 octahedral + 8 tetrahedral per cell, all filled, gives 12 Li for 4 Bi. Idealised ordered model (Zalkin & Ramsey cell constant).
- Idealised ordered model built from the Wyckoff positions of the space group; not a diffraction refinement.
Atom positions (fractional, one cell)
| Atom | x | y | z |
|---|---|---|---|
| Bi | 0.0000 | 0.0000 | 0.0000 |
| Bi | 0.0000 | 0.5000 | 0.5000 |
| Bi | 0.5000 | 0.0000 | 0.5000 |
| Bi | 0.5000 | 0.5000 | 0.0000 |
| Li | 0.5000 | 0.5000 | 0.5000 |
| Li | 0.5000 | 0.0000 | 0.0000 |
| Li | 0.0000 | 0.5000 | 0.0000 |
| Li | 0.0000 | 0.0000 | 0.5000 |
| Li | 0.2500 | 0.2500 | 0.2500 |
| Li | 0.7500 | 0.7500 | 0.2500 |
| Li | 0.7500 | 0.2500 | 0.7500 |
| Li | 0.2500 | 0.7500 | 0.7500 |
| Li | 0.2500 | 0.2500 | 0.7500 |
| Li | 0.7500 | 0.7500 | 0.7500 |
| Li | 0.2500 | 0.7500 | 0.2500 |
| Li | 0.7500 | 0.2500 | 0.2500 |
Z, coordination numbers, distances, density and packing on this page are computed from these coordinates.