Priyanshu Gujjar
Last Activity: 3 Years ago
In the same way, the relation between the radius 'r' and edge length of unit cell 'a' is r = 2a and the number of atoms is 6 in the HCP lattice. Packing efficiency can be written as below, Packing efficiency = Volume occupied by 6 spheres ×100 / Total volume of unit cells. 6 × 4 / 3 π r3 / (2 r)3 × 100% = 74.05%