Question

Packing efficiency of $fcc$ lattice is

• A. $\frac{\pi }{3\sqrt{2}}$
• B. $\frac{\pi }{2\sqrt{3}}$
• C. $\frac{\sqrt{3}\pi }{8}$
• D. $\frac{\pi }{6}$

Answer 1

Answer: (A)

For $FCC$ lattice Packing efficiency
$=\frac{4\times \frac{4}{3}\pi r^3}{a^3}=\frac{\frac{16}{3}\pi r^3}{16\sqrt{2}{r}^3}$
$=\frac{\pi }{3\sqrt{2}}.$