Question

Calculate the number of FCC unit cell

Answer 1

Explanation:

ANSWER

In a FCC lattice there rer 8 atoms at eight corners and 6 at face centers,

Now each corner contributes to eight cells so per unit cell contribution is

81

×8=1 atom.

Now similarly each face center contributes to two unit cells so contribution per unit cell by six face centers is equal to 21

×6=3 atoms. Hence total no. of atoms per unit cell of FCC lattice is (1+3)=4 atoms.

For BCC-

A bcc has one atom in center and 81

th part of 8 corner atoms i.e 1 atom.

In total there are 1+1=2 atoms.

Answer 2

Face center atoms shape per unit cell= 6*(1/2)=3 atoms. The face centered cubic (FCC) has a coordinated