Question

Nearest neighbouring distance between two carbon atoms in a unit cell of diamond is equal to ( a = edge length of the unit cell )​

Answer 1

Answer:

Diamond has fcc unit cell structure made up of atoms.

This accounts for 8×

8

1

+6×

2

1

=1+3=4 C atoms

C atoms are also present in one half of the tetrahedral voids.

There are 8 tetrahedral voids in fcc structure.

This accounts for remaining 8×

2

1

=4 C atoms

Thus, total 4+4=8 C atoms are present per unit cell of diamond.