A First-principles Calculation of Structures and Stability of Al_(13)I Cluster
A First-principles Calculation of Structures and Stability of Al_(13)I Cluster作者机构:School of Materials Science & Engineering Hunan University Changsha 410082 China
出 版 物:《Chinese Journal of Structural Chemistry》 (结构化学(英文))
年 卷 期:2006年第25卷第2期
页 面:232-239页
核心收录:
学科分类:081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 0703[理学-化学] 070301[理学-无机化学]
主 题:Al13I cluster structural stability electronic structure,pseudo-potential plane-wave method
摘 要:Using first-principles pseudo-potential plane wave method, the energetics, geometrical and electronic structures of three Al13I cluster isomers were calculated. The calculation results of the binding energy indicate Al13I cluster is more stable than Al13 cluster although its electrons are not a magic number as in Alia cluster, and among Al13I cluster isomers the "Bridge" structure is the most stable, the second is the "Ontop" structure, and the worst is the "Hollow" structure. By analyzing the geometrical structures of Al13I cluster isomers, it is found that after I atom and Al13 cluster combine the geometrical structures of Al13 moieties are changed besides Al13I Hollow cluster, in which the Alia moiety is still a regular icosahedron. For Al13I Ontop cluster, the Al13 moiety has a shrinking trend to I, whereas in Al13I Bridge cluster it is distorted. Mulliken population analysis shows for the interaction of electrons between Al-I atoms in Al13I cluster not only there exists an ionic bonding but there is a covalent bonding. Part of electrons in the Alia cluster transfer to I as Al13 cluster and I atom combine. The order of the strength of covalent bonding between Al13 moiety and I in Al13I cluster isomers is Al13IBridge〉Al13IHollow〉Al13I Ontop. Further analysis of electric structures of Al13 and Al13I clusters indicates a higher stability of Al13I cluster than Al13 cluster can be attributed to the s-p hybridization of 3s and 3p electrons of Al in Al13 moiety induced by 1 doped, which leads to fewer electrons N(EF) at EF in Al13I and a larger energy gap △EH-L between HOMO and LUMO levels in Al13I cluster. The distinguish of structural stability of Al13I cluster isomers mainly originates from their different magnitudes .in decrease of N(EF) and increase of △EH-L relative to Al13 cluster. The fewest N(EF) and the largest △EH-L are responsible for the high stability of Al13I Bridge cluster.