$CsBr$ crystal has $bcc$ structure. It has an edge length of $4.3 \ \mathring{A}$. The shortest interionic distance between $Cs^{+}$ and $Br^{-}$ ions is ................ $\mathring{A}$.

The number of carbon atoms per unit cell of diamond unit cell is

The face diagonal length of $f.c.c.$ cubic cell is $660 \sqrt{2} \, pm$. If the radius of the cation is $110 \, pm$,the radius of the anion is ............ $pm$.

By increasing the pressure on $NaCl$ crystal,its coordination number will

The coordination number of a metal crystallizing in a hexagonal close-packed $(hcp)$ structure is:

In a compound formed by $A^{+}$ and $B^{-}$ ions,$B^{-}$ ions are arranged at all corners except two and at all face centers except three,while $A^{+}$ ions are at the midpoints of all body diagonals. The molecular formula of the compound will be ................