On the Underlying Source of Energetics of Bending of Hydrogen Bonds
Journal of Molecular Structure: TheoChem
Quantum chemical methods are used to assess the importance of a number of factors contributing to H bond strength. The electrostatic component appears to reproduce fairly well the energetic cost of bending an H bond, either an ionic one such as (H2OH⋯OH2)+ or a neutral pair as in HOH⋯OH2. Expansion of the full Coulombic interaction into its multipole series yields insights into the underlying cause of these distortion energies, in addition to the fundamentally different clustering behavior of K+ and the nearly spherical NH+4. The correction to the electrostatic term that arises at the correlated level appears to be at least as important as dispersion, and to be considerably more anisotropic.
On the Underlying Source of Energetics of Bending of Hydrogen Bonds S. Scheiner J. Mol. Struct., Theochem 1992 256, 1-16.