Question

calculate the number of atoms present in face centered cubic unit cell

Answer 1

Primitive cubic unit cell

In each cubic unit cell there are 8 atoms at the corners, therefore the total number of atoms in one unit cell is: 8×18=1atom

Body centered cubic unit cell:

8 corners ×18 per corner atom = 8×18=1 atom

1 body centre atom = 1×1 = 1 atom

Therefore, total number of atoms present per unit cell = 2 atoms.

Face centered cubic unit cell:

in a face centered cubic unit cell:

8 corners ×18 per corner atom = 8×18=1 atom

6 face-centered atoms ×12 atom per unit cell = 3 atoms

Therefore the total number of atoms in a unit cell = 4 atoms