(湖南大学 材料科学与工程学院，长沙 410082))
摘 要:
关键字: Aln+团簇；分裂机理；密度泛函理论；线性同步转变方法
（School of Materials Science and Engineering, Hunan University, Changsha 410082, China）
Abstract:Based on the experimental result of Aln+m+ clusters decomposed by means of a isolated Al atom or cation, the disassociation route and mechanism of Aln+m+ (n+m≤13) clusters in the Aln ++Alm (n=1−12, m=1−12) mode were investigated by linear synchronous transit（LST）and quadratic synchronous transit (QST) method. Several parameters, such as the ionization potential, the endothermic reaction heat ∆HR-P and the dissociation barrier energy ∆ER-T of Aln+m+ (n+m≤13) clusters were calculated. Comparison of ∆HR-P and ∆ER-T requested in the disassociation route reveals the least energy of a isolated Al atom or cation from the Aln+m+ clusters is related to bigger ∆HR-P and ∆ER-T values, while a big cluster decomposites into two small clusters. The energetics difference between routes should be responsible for the preferential route of dissociation of Aln+ (n=2−13) clusters in terms of Aln+ →Al+ Aln−1+ or Aln+→Al++ Aln−1.
Key words: Aln+ cluster; decomposition mechanism; density functional theory; linear synchronous transit
