Unit cell
- Lattice constants
- a = 3.567 Å, b = 3.567 Å, c = 3.567 Å; α = 90°, β = 90°, γ = 90°
- Cell volume
- 45.4 ų
- Atoms in the cell
- 8 (C 8)
- Formula units Z
- 8
- Calculated density
- 3.52 g cm⁻³
- Shortest contact
- 1.545 Å
Coordination
- C
- CN 4 at 1.54 Å (4 C)
About the structure
- Each carbon is tetrahedrally bonded to four others (C–C 1.54 Å).
- Two interpenetrating ccp lattices, one shifted by ¼ of the body diagonal.
- Si, Ge and grey Sn share this structure; sphalerite is the same framework with two elements.
- Packing efficiency is only 34%: a very open structure held by covalent bonds.
Atom positions (fractional, one cell)
| Atom | x | y | z |
|---|---|---|---|
| C | 0.0000 | 0.0000 | 0.0000 |
| C | 0.0000 | 0.5000 | 0.5000 |
| C | 0.5000 | 0.0000 | 0.5000 |
| C | 0.5000 | 0.5000 | 0.0000 |
| C | 0.2500 | 0.2500 | 0.2500 |
| C | 0.2500 | 0.7500 | 0.7500 |
| C | 0.7500 | 0.2500 | 0.7500 |
| C | 0.7500 | 0.7500 | 0.2500 |
Z, coordination numbers, distances, density and packing on this page are computed from these coordinates.