The Molecular Dynamics Study Of The Dielectric Property For Confined Ice-water Using A Polarizable Model

The dielectric properties of water under limited conditions play an important role in electrochemistry and energy storage,and the different limited conditions,such as limited size and limited temperature,have a strong impact on its properties.However,due to the limitations of experimental conditions,so far,few people can accurately report the dielectric properties of water under ultra-high restrictions,and many simulation reports on the dielectric properties of confined water use the rigid non polarizable water model.In this paper,a set of simulation calculation and analysis method is proposed to study the dielectric properties of nano scale confined water based on polarizable water model.Using this method,we simulate the single molecular layer ice(water)system with rigid fixed charge dipole moment SPC/E water model and polarizable water model SWM4-NDP limited in 0.65 nm size and 5000 bar limited pressure at different temperatures.We analyze the structure of different systems and dielectric properties,by calculating the structure factor,dipole moment distribution of polarizable water model,dielectric tensor at different temperatures,and radial dipole-dipole spatial correlation function.we find that: due to the limitation,the system has strong anisotropy in the x,y and z directions;the two water molecular models have the same effect in describing the static phase structure properties of the limited system;but compared with SPC/E water model,this water model has obvious advantages in describing the polarization dynamic properties of confined water.We conclude that the polarization water model is better than the traditional SPC/E water model in the study of ion transport,structural phase change and solvation dynamic process of confined water.