Sodium Chloride is an alkali halide with an fcc crystal structure. The basis is two ions, a sodium cation and a chlorine anion. The crystal lattice parameter is 0.563 nm. The diagram shows both a unit ...

and in the center of the cube (one more cation). Thus we have four anions (FCC) and four cations, which corresponds with the stoichiometry of the salt (1:1). occupying the tetrahedral holes. Remember ...

For example, sodium chloride is a common salt, and water a common solvent. The salt provides the electrolyte with both cations and negatively charged elements (anions) -; chlorine in the case of ...