A 3D construction model shows how the ions are arranged in a lattice structure. These models usually use coloured balls to represent the ions. Some use sticks to show the ionic bonds. A 3D ...

The lattice arrangement continues in three dimensions. This is why solid ionic compounds form crystals with regular shapes.

Max Born and I have shown that one can obtain a theory of superconductivity by taking account of the fact that the interaction of the electrons with the ionic lattice is appreciable only near the ...