Question

In a bcc, what fraction of edge is not covered by atoms?

• A. $0.32$
• B. $0.16$
• C. $0.134$
• D. $0.268$

Answer 1

Answer: (C)

$0.134$

In an atomic bcc, fraction of edge which is not covered by atoms is
$f=\frac{a-2R}{a}$
$f=\frac{a(1-\frac{2\left(\sqrt{3}\right)}{4})}{a}$
$f=1-\frac{\sqrt{3}}{2}=0.136$