密度泛函理论对NiBe_n(n=2-12)团簇结构和性质的研究  

Density Functional Theory Study on the Structure and Properties of NiBe_n(n=2-12) Clusters

作　　者：葛桂贤[1] 孙茂珠[1] 殷保祥[1] 

机构地区：[1]石河子大学生态物理重点实验室石河子大学师范学院物理系,新疆石河子832003

出　　处：《石河子大学学报（自然科学版）》2008年第6期781-785,共5页Journal of Shihezi University(Natural Science)

摘　　要：采用密度泛函理论中的广义梯度近似对NiBen(n=2-12)团簇的几何构型进行优化,并对能量、频率和磁性进行了计算,同时考虑了电子的自旋多重度。结果表明:团簇的几何结构与自旋多重度有关,最低能量结构的自旋多重度是3和1;n≥4时,较强的p,d杂化导致团簇的磁矩淬灭;与Ben+1(n=2-12)团簇相比,NiBen(n=2-12)团簇的稳定性增强;能隙明显减小,化学活性增强,得出了掺杂Ni原子可以增强团簇稳定性和化学活性的结论;二阶能量差分表明,4,10是团簇的幻数。Geometric structures of NiBen （ n = 2-12） clusters are optimized by using the generalized gradient approximation （GGA） density functional theory. Energy, vibrational frequency and magnetism have been calculated. Tbe results indicate that the spin multiplicities of the ground-state clusters are 3 and 1. The geometric structures, of NiBen clusters are influenced by spin multiplicities. It is found that the magnetic moment of the Ni atom in NiBen clusters is quenched around n≥4,due to strong hybridization between the 4s and 3d states of Ni and the 2s and 2p states of Be. According to the contrast to Ben ＋ 1 cluster, it concludes that impurity increases the stabilities and the chemical activity of Ben＋1 cluster. Furthermore, the investigations on the second energy difference show NiBe4 and NiBe10 clusters are more stable than neighboring ones.

关 键 词：NiBen团簇 自旋多重度 磁矩 电子性质 

分 类 号：O641[理学—物理化学]