Nature of H-bonds in water vapor

The work is devoted to the discussion of the H-bond nature in rare enough water vapor. For achievement of this aim 1) the new inter-particle potential between water molecules is constructed and 2) the overlapping degree of electron shells for water molecules forming an isolated dimer is in details studied. In order to estimate the diameter of a molecule, the averaged inter-particle potential between water molecules is used. It is shown that the overlapping degree does not exceed 0.03 that leads to the conclusion about the electrostatic nature of H-bonds in water vapor.