Discriminating High-Pressure Water Phases Using Rare-Event Determined Ionic Dynamical Properties  

作　　者：Lin Zhuang Qijun Ye Ding Pan Xin-Zheng Li 庄琳;叶麒俊;潘鼎;李新征(Institute of Condensed Matter and Material Physics,School of Physics,Peking University,Beijing 100871;State Key Laboratory for Artificial Microstructure and Mesoscopic Physics,Frontier Science Center for Nano-optoelectronics and School of Physics,Peking University,Beijing 100871;Department of Physics and Department of Chemistry,Hong Kong University of Science and Technology,Hong Kong;HKUST Fok Ying Tiling Research Institute,Guangzhou 511458;Collaborative Innovation Center of Quantum Matter,Peking University,Beijing 100871)

机构地区：[1]Institute of Condensed A latter and Alat erial Physics,School of Physics,Peking University,Beijing 100871 [2]State Key Laboratory for Artificial Microstructure and Mesoscopic Physics,Frontier Science Center for Nano-optoelectronics and School of Physics,Peking University,Beijing 100871 [3]Department of Physics and Department of Chemistry,Hong Kong University of Science and Technology,Hong Kong [4]HKUST Fok Ying Tiling Research Institute,Guangzhou 511458 [5]Collaborative Innovation Center of Quantum Matter,Peking University,Beijing 100871

出　　处：《Chinese Physics Letters》2020年第4期19-25,共7页中国物理快报（英文版）

基　　金：Supported by the National Basic Research Program of China under Grant Nos.2016 YFA0300900 and 2017YFA0205003;the National Science Foundation of China under Grant Nos.11774003.11634001.11934003,and 11774072.D.Pan also acknowledges the support from Hong Kong Research Grands Council(Nos.ECS-26305017 and GRF-16307618);the Alfred R.Sloan Foundation through the Deep Carbon Observatory(DCO);the Croucher Foundation through the Croucher Innovation Award.

摘　　要：Recent discoveries of dynamic ice Ⅶ and superionic ice highlight the importance of ionic diffusions in discriminating high-pressure(P) water phases.The rare event nature and the chemical bond breaking associated with these diffusions,however,make extensive simulations of these processes unpractical to ab initio and inappropriate for force field based methods.Using a first-principles neural network potential,we performed a theoretical study of water at 5-70 GPa and 300-3000 K.Long-time dynamics of protons and oxygens were found indispensable in discriminating several subtle states of water,characterized by proton’s and oxygen ion’s diffusion coefficients and the distribution of proton’s displacements.Within dynamic ice Ⅶ,two types of proton transfer mechanisms,i.e.,translational and rotational transfers,were identified to discriminate this region further into dynamic ice Ⅶ T and dynamic ice Ⅶ R.The triple point between ice Ⅶ,superlonic ice(SI),and liquid exists because the loosening of the bee oxygen skeleton is prevented by the decrease of interatomic distances at high P’s.The melting of ice Ⅶ above ~40 GPa can be understood as a process of two individual steps:the melting of protons and the retarded melting of oxygens,responsible for the forming of SI.The boundary of the dynamic ice VIF and SI lies on the continuation line ice Ⅶ’s melting curve at low P’s.Based on these,a detailed phase diagram is given,which may shed light on studies of water under P’s in a wide range of interdisciplinary sciences.

关 键 词：RARE CONTINUATION STEPS 

分 类 号：O661.1[理学—分析化学]