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    李云国

    • 特任教授 博士生导师
    • 教师英文名称:Yunguo Li
    • 电子邮箱:
    • 学历:研究生(博士)毕业
    • 办公地点:教学行政楼811室
    • 联系方式:0551-63601184
    • 学位:博士
    • 毕业院校:瑞典皇家理工学院
    • 学科:地质学

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    19 Mar 2025

    当前位置: 中文主页 >> News >> 19 Mar 2025

    Paper alert! 

    A paper on water diffusion in silicate melt was published in Physical Review B from our group.

    Dynamic bonding analysis of the water diffusion mechanism in silicate melts

    Water diffusion in silicate melt is an essential process for understanding the transport properties and dehydration kinetics of silicate melt. However, the fast liquid dynamics and interconversion of hydrous species pose a substantial challenge to both experimental and theoretical studies of water diffusion. We developed a bonding analysis method to unambiguously identify stable and transition-state hydrous species, and obtained their characteristic diffusion coefficients from restrained ab initio molecular dynamics simulations. We find that the stable species include a hydroxyl group, molecular water, and a trace amount of hydronium. Proton is only a transition-state species, but proton hopping dominates the overall water diffusion with a contribution over 60%, primarily through triggering the rotational diffusion of the O–H bond. Namely, the coupling of proton hopping and O–H bond rotation leads to fast water diffusion. The uncovered mechanism enables the construction of a water diffusion model based purely on thermodynamics, and extrapolating this model to temperatures below 2000 K aligns well with experimental observations.

    wang1.png

    Figure: Schematic potential energy profiles indicating three possible types of configurations for one H between two O atoms. a H forms a hydroxyl group with the left O and a hydrogen bonding with the right O. b H forms two hydrogen bonding and stays as a stable isolated H between two O atoms. c H forms two covalent bonding with the two O atoms.