Abstract
The importance of the intra‐atomic Hund coupling between electron spins is emphasized to account for the general features of the electron‐coupled interaction between nuclear spins separated by several atoms. This seems to be quite consistent with the experimental results, especially with the appearance of the negative coupling constants in many of the long‐range cases. By using the simple valence‐bond method, the effect of the Hund couplings on the coupling constant between nuclear spins is expressed in terms of the various exchange integrals between adjacent electron orbitals for the cases of one, two, and three intervening atoms.