Metallic Crystal Structures

Important properties of the unit cells are

- The type of atoms and their radii R.

- Cell dimensions (side a in cubic cells, side of base a and height c in HCP) in terms of R.

- n, number of atoms per unit cell. For an atom that is shared with m adjacent unit cells, we only count a fraction of the atom, 1/m.

- CN, the coordination number, which is the number of closest neighbors to which an atom is bonded.

- APF, the atomic packing factor, which is the fraction of the volume of the cell actually occupied by the hard spheres. APF = Sum of atomic volumes/Volume of cell.