Distinguish between
a. Hexagonal and monoclinic unit cells
(b) Face-entred and end-centred unit cells

Explanation

(i) In a hexagonal unit cell :
`a=bnec,alpha=beta=90^(@)and gamma=120^(@)`
In a monoclinic unit cell :
`anebnecand alpha=gamma=90^(@)andbetane90^(@)`
(ii) In a face centred unit cell, constituent particles are located are located at all corners as well as at the centres of two opposite faces.
In end-centred unit cell, constituent particles are located at all the corners as well as at the centres as well as at the centres of two opposite faces. For more details, consult Section 6.