Why, in a primitive cubic cell, do anions sit on the lattice points while the cation fills the lattice hole in the center?
a. Because it is favorable for anions to be as close to one another as possible.
b. Because electrons must be able to move though the delocalized sea of anions.
c. Because energy is lowered by keeping positive charge inside the unit cell.
d. Because cations are smaller than anions and fit better inside lattice holes.