# 8.4: Body Centered Packing


## The Model for Polonium Crystal Structure

Discussion -

O   O  |  If we cut the cube along a face diagonal, the arrangement of
O    |  atoms look like the diagram on the left.
O   O  |     Thus, bd = 4 R

• If the edge of the cube has a length represented by a, and if the radius of the atoms is R, express a as a function of R.

Hint: $$a = \dfrac{4 R}{\sqrt3}$$

Discussion -
a = 4 R / √3