基于机器学习的碳酸盐微观结构与性质  

Microstructure and Properties of Carbonate Salt Based on Machine Learning

作　　者：杨博[1] 路贵民[1] YANG Bo;LU Guimin(National Engineering Research Center for Integrated Utilization of Salt Lake Resources,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学国家盐湖资源综合利用工程技术研究中心,上海200237

出　　处：《华东理工大学学报（自然科学版）》2022年第4期456-466,共11页Journal of East China University of Science and Technology

基　　金：国家自然科学基金(U20A20147)。

摘　　要：采用第一性原理计算、机器学习以及经典分子动力学模拟联用的方法对K_(2)CO_(3)和Na_(2)CO_(3)熔融状态下的结构和性质进行计算,计算结果表明,K_(2)CO_(3)的能量(单位原子能量之和,余同)与受力的均方根误差分别为8.62×10^(−4)eV和4.67×10^(8)eV/m;Na_(2)CO_(3)的能量与受力的均方根误差分别为1.19×10^(−3)eV和5.31×10^(8)eV/m,计算值与文献值吻合较好。K_(2)CO_(3)的密度、比热容和热导率的计算偏差分别约为5.0%、3.3%和8.0%,Na_(2)CO_(3)的密度、比热容和热导率的计算偏差分别约为5.6%、6.0%和3.5%。Molten alkali carbonate are widely concerned as potential thermal storage and transfer materials in solar power utilization.As an effective method in molten salt research,computer simulations have been widely used.Local structure and some physical properties of K_(2)CO_(3)and Na_(2)CO_(3)at different temperatures were calculated by a complex simulation method including first-principle molecular dynamics,machine learning and classical molecular dynamics.In this method,first-principle molecular dynamics offered accuracy structure information,machine learning was used to create deep potential from structure information to describe potential energy of system,and classical molecular dynamics was used to perform large scale simulation.This complex method could reduce calculation errors caused by potential functions and empirical parameters.The calculation results showed that energy and force test errors of K_(2)CO_(3)were 8.62×10^(−4)eV and 4.67×10^(8)eV/m,respectively;energy and force test errors of Na_(2)CO_(3)were 1.19×10^(−3)eV and 5.31×10^(8)eV/m,respectively.In all simulation processes,the carbonate ion was a standard equilateral triangle structure in the system,and carbonate clusters were slightly loosened with the increase of temperature;the distance between anions and cations gradually increased with the increase of temperature.The result showed that simulated data of the property was in good agreement with the literature value.The deviations of density,specific heat capacity and thermal conductivity of K_(2)CO_(3)were about 5.0%,3.3%and 8.0%.The deviations of density,specific heat capacity and thermal conductivity of Na_(2)CO_(3)were about 5.6%,6.0%and 3.5%.

关 键 词：离子结构 熔盐性质 分子动力学 碳酸熔盐 

分 类 号：O552[理学—热学与物质分子运动论]