Illustrated Glossary of Organic Chemistry

Noncovalent molecular force (noncovalent molecular interaction; van der Waals forces): The attractive or repulsive force between atoms and/or molecules, other than covalent bonding. Includes (but not limited to) anion-cation, dipole-dipole, hydrogen bonding, London forces, cation-pi, ion-dipole, and aromatic stacking (pi stacking). Until recently, the terms 'van der Waals force' and 'London force' were used interchangeably, but now 'van der Waals force' is a broad term which refers collectively to all noncovalent forces that operate in a given circumstance.

Evaporation of water requires disruption of two noncovalent molecular forces: hydrogen bonding (a type of dipole-dipole interaction) and London forces.