Water Hydrogen Bond Dynamics under Electric Fiel

An external electric field can change the properties of water enabling numerous applications in science and engineering. Using Molecular Dynamics simulations and Reactive Flux Correlation Function approach we studied the hydrogen bond dynamics and it’s coupling to translational diffusion in the presence of external electric fields. Water dipoles tend to be aligned with the field direction. The alignment rapidly increases with the field strengths below 0.05 V/Å, but water molecules continue to exchange bonding partners at an only slightly reduced rate. At fields stronger than 0.05V/Å, the alignment with the field approaches saturation, but the H-bond exchanging process is more affected, showing a slowdown of bond breaking and increased probability of bond reforming in strong fields. We quantify the change in hydrogen bond forming and breaking rates to be close to 15%, the change in self-diffusion coefficient up to 30% in the field direction, and up to 19% when averaged over all three directions.