Question

In an FCC unit cell, the number of lattice points is

• A. 1
• B. 2
• C. 3
• D. 4

Hint:

FCC (Face-Centered Cubic) structures have the maximum possible lattice points (4) among cubic structures. This makes them highly efficient with a packing efficiency of 74%. FCC structures are common in metals like aluminum, copper, and gold due to their close-packed nature.

Answer 1

The Correct Option is D

In an FCC unit cell, atoms are present at the 8 corners of the cube (each contributing \(1/8\) atom) and at the centers of all 6 faces (each contributing \(1/2\) atom). The total number of lattice points is:
\[\text{Total} = 8 \times \frac{1}{8} + 6 \times \frac{1}{2} = 1 + 3 = 4\]