An expression for three-body interactions in intermolecular forces. These dipole dispersion terms, called Axilrod–Teller terms (named after B. M. Axilrod and Edward Teller, who discovered them in 1943) are of importance in the third virial coefficient. At low temperatures, the Axilrod–Teller terms can have a comparable size to two-body interactions, making them of importance to such properties of liquids as pressure and surface tension. The Axilrod–Teller formula for the dispersion energy V of three closed-shell atoms A, B, and C is given by

where C₆ is a coefficient depending on the identity of the atoms, C′ is a coefficient depending on another constant and the angles between the atoms, and the r terms give distances between the indicated atoms.