van der Waals Dipole-Dipole Interaction between Carbon and Hydrogen and between Oxygen and Hydrogen Atoms

The dipole-dipole dispersion force between carbon and hydrogen and between oxygen and hydrogen was calculated by many-body perturbation theory. Unperturbed orbitals of carbon and oxygen were calculated in a $V^{N-1\mathrm{}}$ potential. Many-body diagrams were evaluated in second and third order. Estimates of higher-order diagrams were made by geometric summation. The values obtained for $C_6$ for C-H were 14.4 a.u. in the $\Sigma$ state and 14.8 a.u. in the $\Pi$ state. For O-H a value of 9.13 a.u. was obtained for the $\Sigma$ state and a value of 9.22 a.u. was obtained for the $\Pi$ state.