Q3: Answer the following questions about body-centered cubic (BCC) structure with the lattice parameter "a". (1) Obtain the volume of void, supposing the case where the spherical atoms of radius rA are arranged in each lattice point. Calculate also the porosity and packing fraction. (2) The position of the maximum void in this body-centered cubic lattice is known to be corresponding to the tetrahedral site (1/2,1/4,0), and to equivalent position. Obtain the radius of maximum sphere that fits to this space