What is the main difference between van der Waals forces and dispersion forces? This statement confuses me: "van der Waals forces are nearly the same thing as dispersion forces." Right now, I have an idea that van der Waals forces includes these attractions: 1. permanent dipole - permanet dipole force such as H-bonding 2. permanent dipole - induced dipole forces 3. instantaneous induced dipole - induced dipole dispersion forces I have observed that van der Waals forces are sometimes used as an synonym for intermolecular forces. I am not sure this completely correct. In my opinion, dispersion forces are then again a subgroup of van der Waals forces which arise from the interactive forces between temporary multipoles in molecules without permanent dipoles. Please, let me know the main difference between van der Waals forces and dispersion forces?