What is the coordination number (C.N.) of an atom in (i) primitive cubic unit cell (ii) body-centred cubic unit cell (iii)face-centred cubic unit cell .

What is the coordination number (C.N.) of an atom in (i) primitive cub

1.	What is the coordination number (C.N.) of an atom in (i) primitive cubic unit cell (ii) body-centred cubic unit cell (iii)face-centred cubic unit cell .
Answer» Solution :(i)In a primitive cubic unit cell, each atom has 6 equally spaced nearest NEIGHBOURS . (II)In BCC, an atom at the body centre is surrounded by 8 nearest neighbours situated at the corners of the CUBE. Hence, C. N. =8. (iii) In FCC, an atom is surrounded by 12 nearest neighbours (6 in its own plane, 3 above and 3 below). Hence , C.N. =12