Quasiphase transition of a single-file water chain influenced by atomic charges in a water model using orientational-biased replica exchange Monte Carlo simulations

作     者：Liang Zhao Junqing Ni Zhi Zhu Yusong Tu Chunlei Wang 

作者机构：College of Physical Science and Technology and Microelectronics Industry Research Institute Yangzhou University Jiangsu 225009 China School of Optical-Electrical Computer Engineering University of Shanghai for Science and Technology Shanghai 200093 China College of Sciences Shanghai University Shanghai 200444 China 

出 版 物：《Physical Review E》 (Phys. Rev. E)

年 卷 期：2025年第111卷第1期

页      面：015419-015419页

核心收录：

基　　金：Shanghai Snow Lake Technology Co., Ltd National Natural Science Foundation of China, NSFC, (11605151, 12074394, 12075201, 12374214) National Natural Science Foundation of China, NSFC Shanghai Rising-Star Program, (23QA1404200) Shanghai Rising-Star Program National Science Fund for Outstanding Young Scholars, (12022508) 

主　　题：Hydrogen bonds 

摘      要：The recently observed temperature-dependent quasiphase transition of the single-file water chain confined within a carbon nanotube in experiments has been validated by the simple lattice theory and molecular dynamics simulations. It has been pointed out that the atomic charges in water models are important, yet how the values will affect the structural details and thermodynamic properties of the quasiphase transition has not been fully revealed. In this work we perform orientational-biased replica exchange Monte Carlo simulations in the canonical ensemble to explore the effect of atomic charges in the SPC/E water model on the quasiphase transition of a single-file water chain. Based on the atomic charge values reported in literature, three distinct quasiphases are reproduced, comprising a fully hydrogen-bonded water chain at lower temperatures, a more ordered dipolar orientation along the tube axis at intermediate temperatures, and a completely disordered structure at higher temperatures. Then by increasing the atomic charge values, we find that the fragmentation of the entire water chain into shorter water segments, the orientational ordering of water dipoles along the tube axis, and the transition towards complete disorder are all inhibited. Consequently, the transition temperatures between three quasiphases have been shifted to higher temperatures. The thermodynamic analysis demonstrates that the increased atomic charge values enhance the hydrogen bonding between neighboring water molecules and also the electrostatic attraction within the water chain, leading to a longer water dipole correlation length even at higher temperatures. These findings highlight the vital role of atomic charges in water models and also the electrostatic interaction in regulating the orientational ordering of water molecules under nanoconfinement.