The energy-partitioning technique developed by us recently has been applied to the binding energies calculated from a modified CNDO method for selected compounds in the saturated hydrocarbon, amine, alcohol, and ether series. The binding energy is partitioned into energy terms that are representative of atom-pair interactions. Calculated results are analyzed in light of existing theoretical and empirical evidence and useful trends are deduced based on the relative magnitudes of these terms. Specifically, the values for the bonded interactions compare exceedingly well with the empirical bond energy values; but those for the nonbonded interactions are drastically reduced owing to the approximation of zero differential overlap empolyed in the CNDO model. Nonetheless, the knowledge of the attractive and repulsive nature revealed by these MO calculations for the various nonbonded interactions is important to the understanding of conformational properties of molecules. © 1979 American Institute of Physics.