In which pair most efficient packing is present?
(i) hcp and bcc
(ii) hcp and ccp
(iii) bcc and ccp
(iv) bcc and simple cubic cell
The answer is the option (ii)
Packing efficiency is defined as the percentage of space occupied by constituent particles in a unit cell.
Packing efficiency of various types of unit cell are:
simple cubic cell - 52.4% .
body centred cubic cell- 68
cubic closed packing- 74%