Q. In BCC cubic system, the value of packing fraction and distance between nearest neighbours, respectively are

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$\frac{\text{\pi } \sqrt{3}}{8},\frac{\sqrt{3}}{2}a$

$\frac{\text{\pi }}{6},a$

$\frac{64}{\sqrt{3}}\text{\pi },\frac{a}{\sqrt{2}}$

$\frac{\text{\pi }}{6},2a$

Solution:

Packing fraction in $BCC=\frac{\sqrt{3}}{8}\pi $
Nearest neighbour in $BCC=\frac{\sqrt{3}}{2}a$

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