Homogeneous connectivity of potential energy network in a solidlike state of water cluster

Authors

Takuma Akimoto, Keio University, Yokohama
Toshihiro Kaneko, Keio University, Yokohama
Kenji Yasuoka, Keio UniversityFollow
Xiao Cheng Zeng, University of Nebraska-LincolnFollow

Date of this Version

2013

Citation

http://dx.doi.org/10.1063/1.4811289

Comments

Used by permission.

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 trappingtime 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, (H₂O)₆ and (H₂O)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.