Identify the unit cell from the following that contains four particles in it.

If $Z$ is the number of atoms in the unit cell that represents the closest packing sequence $ABCABC$,the number of tetrahedral voids in the unit cell is equal to

An example of fluorite structure is

What is the coordination number of the $Ca^{2+}$ ion in the fluorite structure?

In the $NaCl$ structure,what is the position of $Cl^-$ ions?

If three elements $X$,$Y$ and $Z$ crystallise in a $ccp$ lattice with $X$ atoms at the corners,$Y$ atoms at the cube centre and $Z$ atoms at the edges centre,the formula of the compound will be