INDO localized molecular orbitals (LMO's) are utilized for investigating the nature of intermolecular hydrogen bonding in the fully geometry optimized dimers (HFh, (Hz0)2, (NH3)2, FH-OH2, HOH-FH, FH-NH3, H 2NH-FH, H20-HNH2, HOH-NH3, HCN-HF, and HzCO-HF. The results suggest that a reasonable measure of relative hydrogen bond strengths should be the intra bond, two-center, one-electron interference energy connecting the acceptor atom and donated proton. This approach views the net stabilization energy of a hydrogen bonded dimer as arising from a large energy decrease due to formation of the hydrogen bond, modified by smaller energy increases due to internal decreases in monomer bond energies upon formation of the dimer. Hydrogen bond stabilization app.ears to be closely related to the extent of charge transfer within the hydrogen bonded complex. The calculated transfer of charge can largely be explained in terms of electron density shifts within the acceptor lone pairs, while the decrease in electron density on the proton is discussed in terms of the donor XH bond. The approach presented should be particularly useful for analyzing intramolecular hydrogen bonding systems where the hydrogen bond energy is not simply obtainable from monomer-dimer energy differences.