Giant ionic lattice

In an ionic compound, this attraction holds positive and negative ions together in a giant ionic lattice: a regular, repeating arrangement extending in three dimensions.

A solid ionic compound is not a collection of separate pairs of ions. It forms a giant ionic lattice: a regular, repeating arrangement of very large numbers of ions in three dimensions. Each ion is attracted to neighbouring ions of the opposite charge, so strong electrostatic attractions act throughout the structure in all directions.