Lattice:HCP
HCP (Hexagonal close-packed) is a hexagonal lattice. It is notable (along with FACC) because it achieves the densest possible packing of spheres. It thus arises naturally in many atomic crystals, as well as in colloidal crystals and nanoparticles superlattices.
Canonical HCP
In the canonical HCP, the ratio between the a and c distances is:
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \frac{c}{a} = 2 \sqrt{ \frac{2}{3} } = \frac{2\sqrt{6}}{3} \approx 1.633 }
Examples
Elemental
- 4. Beryllium (Be) (a = b = 2.290 Å, c = 3.588, c/a = 1.567)
- 27. Cobalt (Co) (a = b = 2.5071 Å, c = 4.0695, c/a = 1.623)
- 48. Cadmium (Cd) (a =b = 2.9794 Å, c = 5.6186 Å, c/a = 1.886)
Atomic
- TBD
Nano
- Gold nanoparticles
- Stoeva et al. Face-Centered Cubic and Hexagonal Closed-Packed Nanocrystal Superlattices of Gold Nanoparticles Prepared by Different Methods J. Phys. Chem. B 2003, 107 (30), 7441-7448 doi: 10.1021/jp030013+
