Compton Scattering Evidence for Covalency of the Hydrogen Bond in Ice

Periodic intensity variations in the measured Compton profile anisotropies of ordinary ice I sub h correspond to distance of 1.8 angstroms and 3.0 angstroms which are close to the hydrogen bond length and the nearest-neighbor O-O distance, respectively. We intrepret this result as direct evidence for the covalent nature of the hydrogen bond. Very good quantitative agreement between the data and a fully quantum mechanical bonding model for ice I sub h, and the disagreement with a purely electrostatic (classical) bonding model support this interpretation and demonstrates how exquisitely sensitive Compton scattering is to the phase of the electronic wavefunction.