Fe_n、Ni_n(n=2～100)团簇基态结构与能量的模拟淬火算法研究  

Study of the ground-state structural and energetic properties of Fe_n,Ni_n(n=2～100) clusters by using the simulated quenching method

作　　者：阿布来提·阿布力孜[1] 买力坦·开来木[1] 热比古丽·图尔荪[1] 姜园园[1] 段海明[1] 

机构地区：[1]新疆大学物理科学与技术学院

出　　处：《原子与分子物理学报》2013年第6期933-940,共8页Journal of Atomic and Molecular Physics

基　　金：新疆维吾尔自治区自然科学基金(2011211A008)

摘　　要：采用Gupta多体势结合分子动力学模拟退火及淬火方法，分别求解了Fen及Nin（n=2～100）团簇的最低能几何结构及能量．结果表明：在所研究尺寸范围内除少数团簇的结构不同外，两类团簇具有相似的基态几何结构，在两类团簇结构演化中皆存在类Ik、类Oh、类Dsh和Ih＆D5h互嵌套类构型之间的竞争；分析团簇二阶差分能和剩余能表明两类团簇共同的幻数序列为：n=13、19、23、38及55，不同处为Ni26及Fe75也分别为相应体系幻数团簇．对两类团簇分析其平均最近邻原子间距及平均配位数均可给出幻数成因．在所研究团簇尺寸范围内二者平均结合能均表现出随团簇尺寸增大而总体增大的普遍趋势，但Ni团簇的能量演化明显快于Fe团簇，这与实验观测镍团簇磁性演化明显快于铁团簇是完全一致的．The ground-state geometries and energies of Fe. and Nin（n=2～100） clusters are investigated by using Gupta potential combined with the molecular dynamics simulated annealing method and the simulated quenching method. Our results show that： Similar ground-state geometries hold for the two types of clusters in most eases, and there all exist structural competitions between the Ih-like,Oh-like, D5h-like and mutual nested of Ih＆D5h-like structures in the structural evolution of both types of clus- ters. Through analyzing the second-order difference energies and the excessive energies, same magic- number sequence of n=13,19,23,38 and 55 can be obtained for both types of clusters, and with the ex- ception of Ni26 and Fe75 clusters which can also be the magic-number clusters. The origin of the magic numbers of both clusters can be explained by analyzing the average coordination numbers and average nearest neighbor distances. The average binding energies of both clusters increase in general with in- creasing the cluster size,and the speed of energy evolution of Ni clusters is clearly faster than that of Fe clusters which is in accordance with the experimental observations that the evolution of magnetic mo- ments of Ni clusters is evidently faster than that of Fe clusters.

关 键 词：GUPTA势 团簇 基态 分子动力学 模拟淬火 

分 类 号：O469[理学—凝聚态物理] O561.1[理学—电子物理学]