Which of the following is not true about the ionic solids?

The fraction of octahedral or tetrahedral voids occupied depends upon the radii of the ions present at the lattice points. As we know the radii of octahedral or tetrahedral void isrelated to radii of atoms (r) as Radius of octahedral void (Ro) = 0.414 rRadius of tetrahedral void (Rt) = 0.225 rwhere, r = radius of bigger atom involved.