Topic summary
Keesom force
Extracted from the Wikipedia article Intermolecular force.
Keesom force (permanent dipole – permanent dipole)
The first contribution to van der Waals forces is due to electrostatic interactions between rotating permanent dipoles, quadrupoles (all molecules with symmetry lower than cubic), and multipoles. It is termed the Keesom interaction, named after Willem Hendrik Keesom. These forces originate from the attraction between permanent dipoles (polar molecules) and are temperature-dependent.