As mentioned earlier, hydrogen and helium are small gases that are known to be nonformers of hydrates. Even when they are in a mixture with hydrate formers present, they do not enter the hydrate lattice despite their small size.

It is believed that van der Waals forces between the guest and the host molecules are the reason for stabilization of the hydrate crystal. Furthermore, the van der Waals forces are believed to be a result of the electrons in a compound. Hydrogen (H ₂) and helium have only two electrons per molecule, and thus the van der Waals forces are weak. This is one explanation why these small molecules do not form hydrates.