Homogeneous Connectivity of Potential Energy Network in a Solidlike State of Water Cluster

TL;DR

This paper introduces a homogeneous network model to explain the exponential trapping-time distribution in solidlike states of water clusters, supported by molecular dynamics simulations showing exponential and Weibull distributions for different trapping times.

Contribution

The study proposes a simple homogeneous network model to elucidate the exponential trapping-time distribution in solidlike water clusters, validated by molecular dynamics simulations.

Findings

Trapping-time distribution in solidlike states is exponential.

Interevent times within solidlike states follow Weibull distribution.

Transition dynamics between states are well described by the SHN model.

Abstract

A novel route to the exponential trapping-time distribution within a solidlike state in water clusters is described. We propose a simple homogeneous network (SHN) model to investigate dynamics on the potential energy networks of water clusters. In this model, it is shown that the trapping-time distribution in a solidlike state follows the exponential distribution, whereas the trapping-time distribution in local potential minima within the solidlike state is not exponential. To confirm the exponential trapping-time distribution in a solidlike state, we investigate water clusters, $($H${}_2$O$)_6$ and $($H${}_2$O$)_{12}$, by molecular dynamics simulations. These clusters change dynamically from solidlike to liquidlike state and vice versa. We find that the probability density functions of trapping times in a solidlike state are described by the exponential distribution whereas those of interevent times of large fluctuations in potential energy within the solidlike state follow the Weibull distributions. The results provide a clear evidence that transition dynamics between solidlike and liquidlike states in water clusters are well described by the SHN model, suggesting that the exponential trapping-time distribution within a solidlike state originates from the homogeneous connectivity in the potential energy network.