Hcp Unit Cell Diagram. Similarly one may ask what is the atomic packing factor for the hcp crystal structure. C a 8 3 1633 2 page 3 2.
A more typical representation of the hexagonal close packed structure is shown in the figure below. For unit cells generally lattice points that are shared by n cells are counted as 1 n of the lattice points contained in each of those cells. Similarly one may ask what is the atomic packing factor for the hcp crystal structure.
The top and bottom layers contain six atoms at the corners of a hexagon and one atom at the center of each hexagon.
In a hexagonal close packed hcp arrangement of atoms the unit cell consists of three layers of atoms. Click on the unit cell above to view it rotating. This is a rhombohedral cell. These unit cells stack together like this.