Nature of Hydrogen Bond in Water

Abstract

The work is devoted to the investigation of the physical nature of H-bonds. The H-bond potential ΦH (r, Ω ) is studied as an irreducible part of the interaction energy of water molecules. It is defined as a difference between the generalized Stillinger–David potential and the sum of dispersive and multipole interactionpotentials. The relative contribution of ΦH (r, Ω ) to the intermolecular potential does not exceed (10–15)%.

Physical Nature of Hydrogen Bond

“…At the same time, the hydrogen bond energy, as a rule (see work [49]), is associated with the sum of two last terms,…”

“…In order to estimate the irreducible contribution to the hydrogen bond energy, the following approach was proposed in work [49]. From the conventional viewpoint, the ground state energy of a water dimer is determined by the "hydrogen bond" energy E H (r d , Ω d ), where the subscript d indicates that the distance between the oxygen atoms of two water molecules and the angle values correspond to the dimer configuration.…”

“…( 18) that describes the component emerging owing to the overlapping of electron shells in water molecules. In work [49], the intermolecular potential Φ(r, Ω) was simulated by the generalized Stillinger-David potential Φ GSD (r), so that…”

Dimerization of Water Molecules. Modeling of the Attractive Part of the Interparticle Potential in the Multipole Approximation

“…2.57 0.37 -2.94 [3] 2.34 0.43 -1.17 [13] -0.09 -1.67 1.75 [18] -0.07 -1.61 1.69 [23] -0.19 -1.58 1.77 [24] -0.07 -1.61 1.69 [25] -0.55 -0.84 1.39 [26] -0.07 -1.74 1.81 which take the form…”

“…Under the sufficient proximity of water molecules that leads to the overlap of the electron shells, it is necessary to use the quantum chemical calculations to determine the interaction energy. It was shown in [3] that the energy of a hydrogen bond itself does not exceed ∼ k B T m . The last circumstance is in agreement with the fact that the intramolecular distances in a water molecule change not more than by (1 ÷ 3)% [4,5].…”