Modulation of structure and dynamics of water under alternating electric field and the role of hydrogen bonding

Abstract

Using Molecular Dynamics simulations, we investigate the effect of alternating (AC) electric field on static and dynamic properties of water. The central question we address is how hydrogen bonds respond to perpetual field-induced dipole reorientations. We assess structural perturbations of water network and changes of hydrogen bond dynamics in a range of alternating electric field strengths and frequencies using a non-polarisable water model, SPC/E, and two distinct polarisable models: SWM4-NDP and BK3. We confirm that AC field causes only moderate structural perturbations. Dynamic properties, including the rates of bond breaking, switching of hydrogen-bonding partners, and diffusion, accelerate with the strength of AC fields. All models reveal a nonmonotonic frequency dependence with fastest dynamics at frequencies around 200 GHz where the period of the field oscillation is commensurate with the average time it takes a typical proton to switch from one acceptor to another. Higher frequencies result in smaller amplitudes of angle oscillations and in reduced probability to complete the switch to another acceptor before the field reversal restores the original configuration. As frequency increases, these effects gradually weaken the influence of the field on the kinetics of hydrogen bonding and the associated rates of translational and rotational diffusion in water.

GRAPHICAL ABSTRACT

KEYWORDS:

• Oscillatory field
• hydrogen bond dynamics
• switching between proton acceptors
• anisotropic diffusion
• nonmonotonic frequency dependence

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Dusan Bratko http://orcid.org/0000-0002-3675-5275

A. Luzar http://orcid.org/0000-0003-1640-191X

Additional information

Funding

While performing this work, M.S., N.O., and A.L. were supported by the National Science Foundation under Grant No. CHE-1800120 and S.Z., and D.B. were supported by the Office of Basic Energy    Sciences, Chemical Sciences, Geosciences, and Biosciences Division of the U.S. Department of Energy (Grant No. DE-SC 0004406). We acknowledge the supercomputer time from Extreme Science and Engineering Discovery Environment  (XSEDE), supported by NSF Grant No. OCI-1053575, and the National Energy Research Scientific Computing Center (NERSC), supported by the Office of Science of the U.S. Department of Energy (No. DEAC02-05CH11231).