Weighted multibody expansions for computing stable structures of multiatom systems

作     者：Veera Sundararaghavan Nicholas Zabaras 

作者机构：Materials Process Design and Control Laboratory Sibley School of Mechanical and Aerospace Engineering Cornell University Ithaca NY 14853-3801 United States 

出 版 物：《Physical Review B》 (Phys. Rev. B Condens. Matter Mater. Phys.)

年 卷 期：2008年第77卷第6期

页      面：064101-064101页

核心收录：

学科分类：0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 07[理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

摘      要：The effect of structural relaxations in alloys is described using a multibody energy expansion formalism. N-body potentials in the multibody expansion are computed from energies of isolated clusters, which, in turn, are calculated from empirical potentials or self-consistent quantum mechanical calculations. Convergence characteristics of multibody expansions (MBEs) are improved by weighting energies obtained from various truncations of many-body expansions in a method called weighted MBE (WMBE). It is shown that multibody expansions of many-atom systems can be efficiently constructed using interpolation of isolated cluster energies from databases. In contrast to the method of cluster expansion, WMBE focuses on positional degrees of freedom and, hence, explicitly handles structural relaxations during computations of stable atom clusters and periodic or amorphous phase structures.