逆向蒙特卡罗模拟在无序体系中的应用

Reverse Monte Carlo applications in disordered systems

晶体学只能够给出有关晶体平均原子结构的信息,而结合逆向蒙特卡罗(Reverse Monte Carlo,RMC)模拟的全散射方法将同时包含原子的平均结构和局部尺度上原子间距、键角以及结构多面体的取向和形变等方面的信息,这也是RMC方法一个独特的优势.近年来,借助第三代同步辐射加速器和散裂中子源,RMC方法在实验和理论上都有了较快的发展,同时数据质量高,保证了该方法在材料的局域波动和无序的精细结构研究中的适用性.本文从RMC基本原理和分析方法两个方面介绍了无序体系中的逆向蒙特卡罗方法,同时给出了一系列有助于理解的RMC模型实例.最后,对RMC方法的发展进行了展望.近年来我国对大科学装置的投入迅速增长,相信RMC方法搭载第四代高能量光源,必将在我国新材料的设计与开发中发挥重要的作用.

Crystallography can only provide information about the average atomic structure of a crystal.However,the full scattering method combined with the Reverse Monte Carlo(RMC)simulation has a unique advantage of providing multiple information regarding a crystal,including the average atomic structure,atomic spacing,bond angles,orientation,and deformation of the structural polyhedron at the local scale.Recently,with the help of the third-generation synchrotron and spallation neutron sources,the RMC method has undergone rapid experimental and theoretical development.Additionally,owing to its high-quality data,the RMC method is widely used to study the local fluctuations and fine structure of disordered materials.This paper introduces the RMC method in a disordered system by describing its basic principles and analysis methods and illustrates a series of RMC model cases beneficial for us to understand the RMC method.Finally,the future development of the RMC method is discussed.Recently,China’s investment in research equipment for universities has grown exponentially,and we believe that the RMC method with the fourth generation of high-energy light sources will play an important role in the design and development of various novel materials.