An intermolecular force is an attractive (or repulsive) force that acts between separate molecules or particles. Such forces are much weaker than the covalent or ionic bonds within a molecule, but they determine physical properties such as melting point, boiling point, and solubility. They include van der Waals forces and the stronger hydrogen bond.

分子间作用力是作用于不同分子或粒子之间的吸引(或排斥)力。这类作用力比分子内部的共价键或离子键弱得多,却决定着熔点、沸点和溶解度等物理性质。它们包括范德华力和较强的氢键。