Condensed phase electron decomposition analysis based on density functional theory has recently revealed an asymmetry in the hydrogen-bond network in liquid water, in the sense that a significant population of water molecules are simultaneously donating and accepting one strong hydrogen-bond and another substantially weaker one. Here we investigate this asymmetry, as well as broader structural and energetic features of water's hydrogen-bond network, following the application of an intense electric field square pulse that invokes the ultrafast reorientation of water molecules. We find that the necessary field-strength required to invoke an ultrafast alignment in a picosecond time window is on the order of 10sup8/sup?Vmsup-1/sup. The resulting orientational anisotropy imposes an experimentally measurable signature on the structure and dynamics of the hydrogen-bond network, including its asymmetry, which is strongly enhanced. The dependence of the molecular reorientation dynamics on the field-strength can be understood by relating the magnitude of the water dipole-field interaction to the rotational kinetic energy, as well as the hydrogen-bond energy.
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