Dispersion forces

Dispersion forces

or London forces occur particularly in dipole-free molecules and atoms, and are attributable to rapidly changing charge distributions that arise as a result of electron density fluctuations. Like van der Waals forces, dispersion forces are also of an electrostatic nature, and have an extremely short range. They are normally regarded as special-case van der Waals forces. In non-polar molecules, they are the only cause of van der Waals attraction.