An Explanation of the Unusual Strength of the Hydrogen-Bond in Small
Water Clusters
Abstract
We seek to explain why the hydrogen bond possesses unusual strength in
small water clusters that account for many of the complex behaviors of
water. We have investigated and visualized the donation of covalent
character from covalent (sigma) to hydrogen-bonds, by calculating the
eigenvector coupling properties of QTAIM, stress tensor σ(r) and
Ehrenfest Force F(r) on the F(r) molecular graph. The next generation
3-D bond-path framework sets are presented and only the F(r) bond-path
framework sets reproduce the earlier finding on the coupling between
covalent (sigma) and hydrogen-bonds that possess a degree of covalent
character. The directional character of the covalent (sigma) and
hydrogen-bonds 3-D bond-path framework sets for the F(r) explains
differences found in the earlier results from QTAIM and the stress
tensor σ(r).