Nature of Hydrogen Bond in Water
  The work is devoted to the investigation of physical nature of H-bond. The H-bond potential $\Phi_{H} (r,\Omega)$ is studied as an irreducible part of the interaction energy of water molecules. It is defined as a difference between generalized Stillinger-David potential and the sum of dispersive and multipole interaction potentials. Relative contribution of $\Phi_{H} (r,\Omega)$ to intermolecular potential does not exceed (10\div15)%. 
Paul Makhlaichuk, Mykola Malomuzh, Igor Zhyganiuk
physics.chem-ph