Unit cell
- Lattice constants
- a = 5.640 Å, b = 5.640 Å, c = 5.640 Å; α = 90°, β = 90°, γ = 90°
- Cell volume
- 179.4 ų
- Atoms in the cell
- 8 (Na 4, Cl 4)
- Formula units Z
- 4
- Calculated density
- 2.16 g cm⁻³
- Shortest contact
- 2.820 Å
Coordination
- Na
- CN 6 at 2.82 Å (6 Cl)
- Cl
- CN 6 at 2.82 Å (6 Na)
About the structure
- ccp array of Cl⁻ with Na⁺ in every octahedral hole.
- Coordination 6:6; radius ratio 0.54, in the octahedral range 0.414–0.732.
- Two interpenetrating fcc lattices offset by half a cell edge.
- LiF, MgO, CaO, AgCl, PbS and most alkali halides share this structure.
Atom positions (fractional, one cell)
| Atom | x | y | z |
|---|---|---|---|
| Na | 0.5000 | 0.5000 | 0.5000 |
| Na | 0.5000 | 0.0000 | 0.0000 |
| Na | 0.0000 | 0.5000 | 0.0000 |
| Na | 0.0000 | 0.0000 | 0.5000 |
| Cl | 0.0000 | 0.0000 | 0.0000 |
| Cl | 0.0000 | 0.5000 | 0.5000 |
| Cl | 0.5000 | 0.0000 | 0.5000 |
| Cl | 0.5000 | 0.5000 | 0.0000 |
Z, coordination numbers, distances, density and packing on this page are computed from these coordinates.