What is the crystal structure of $\mathrm{NaCl}$ ?

Sodium chloride $\left(\mathrm{NaCl}\right)$ has face centred cube structure. It contains $4{\mathrm{Na}}^{+}$and $4{\mathrm{Cl}}^{-}$ions. Each ${\mathrm{Na}}^{+}$ion is surrounded by $8{\mathrm{Cl}}^{-}$ ions and each $\mathrm{Cl}$ ion is also surrounded by $8{\mathrm{Na}}^{+}$ions.