Van der Waals intermolecular forces consist of
- London dispersion force between random and induced dipoles, that applies to oxygen molecules. These are the weakest.
- Debye force between permanent and induced dipoles
- Keesom force between 2 permanent dipoles. These are the strongest.
The induction of dipoles in molecules, bonds or atoms can be caused by an external large scale electrostatic field or by nearby presence of ions, permanent or temporary (random or induced) dipoles.
See also Intermolecular force
For chemistry of low temperatures and high pressures, see tetraoxygen and octaoxygen, with the latter forming a nice brick-like structure:
As the pressure of oxygen at room temperature is increased through 10 gigapascals (1,500,000 psi), it undergoes a dramatic phase transition to a different allotrope. Its volume decreases significantly,and it changes color from sky-blue to deep red.