HEXAGONAL CLOSEPACKED STRUCTURE
PACKING FRACTIONS 3 3 4 32 a fraction a S 3 3 atoms cell 42 4 ( ) 34 2 6 V V a fraction a S S u a 2 a CCP (and HCP) BCC 2 4 a radius 3 3 43 2 ( ) 34 a fraction a u S 3 4 a radius SC 74% 68% 52% The fraction of the total crystal volume that is occupied by spheres 84