Average energy approximations for anisotropic triple-dipole dispersion energy coefficients using three-body interactions involving O2, NO, CO, N2, H2, and the rare gases as tests

Average energy approximations for the anisotropic triple-dipole dispersion energy coefficients are tested using reliable results for these coefficients, which are available for all interactions involving the rare gases, H-2,N-2, CO, O-2, and NO. The original average energy approximation does not reproduce any of the anisotropic coefficients to within their estimated uncertainties. More recently derived average energy approximation formulae, requiring the isotropic and anisotropic polarizabilities and average energies for the interacting species as input, reproduce all but 69 of the 680 isotropic and anisotropic coefficients considered to within their estimated uncertainties.