What is the limiting radius ratio for a tetrahedral shape?

The radius of divalent cation $A^{+2}$ is $94 \, pm$ and divalent anion $B^{-2}$ is $146 \, pm$. The structure of compound $AB$ is

Which type of cubic lattice has the maximum number of atoms per unit cell?

How is the anti-fluorite structure derived from the fluorite structure?

Which among the following crystal lattices occupies all of the cubic holes by cations?

An ionic solid $AB$ crystallizes in a $NaCl$-type structure,where $A$ ions are at the corners of the cube. If all face-centered ions along one axis are removed,then the stoichiometry of the resulting solid will be .....