Question

what is the packing efficiency Fcc, Bcc and simple cubic unit cell

Answer 1

The packing efficiency is the percentage of total space occupied by the particles.

The packing efficiency of Fcc unit cell is 74%.
The packing efficiency of Bcc unit cell is 68%.
The packing efficiency of simple cubic unit cell is 52.4%.

Answer 2

Both ccp and hcp are highly
efficient lattice; in terms of
packing. The packing efficiency
of both types of close packed
structure is 74%, i.e. 74% of the
space in hcp and ccp is filled. The
hcp and ccp structure are equally
efficient; in terms of packing.
The packing efficiency of simple
cubic lattice is 52.4%. And the
packing efficiency of body
centered cubic lattice (bcc) is
68%.