Question

How many atoms are present in a face centred cubic unit cell?

Answer 1

Face centred cubic unit cell:

• When the constituent particle is present at the centre of each face, it is known as the Face Centred Unit cell.
• The face-centred cubic (FCC) has a coordination number of 12.
• One-eighth of an atom at each of the eight corners i.e $8\times 1/8=1$ atom from the corners.
• One-half of an atom on each of the six faces i.e $6\times 1/2=3$ atoms from the faces.

Hence, there is a total of 4 atoms in a face centred cubic unit cell.