Mgn^-,AlMgn-1(n=2～13)团簇结构和电子性质的密度泛函理论研究  

Density functional theory study of structures and electronic properties of Mg_n^- and AlMg_(n-1)(n=2～13) clusters

作　　者：王志强[1] 田付阳[1] 田凯[2] 

机构地区：[1]河南大学人事处及物理与电子学院,开封475004 [2]黄河科技学院信息工程学院,郑州450005

出　　处：《原子与分子物理学报》2008年第2期439-445,共7页Journal of Atomic and Molecular Physics

摘　　要：本文从第一性原理出发,利用密度泛函理论的B3PW91方法,在6-311G水平上对Mgn-,Al Mgn-1(n=2 ～13)团簇进行了几何结构优化和频率分析,并对团簇的平均结合能,二阶能量差分,劈裂能等进行了计算.结果表明:与Mgn团簇相比,带负电Mgn-团簇的最低能量结构整体(除n=6 ,8 ,11)变化不大.Al原子的掺杂对Mgn(n=2 ～13)团簇的最低能量结构没有太大影响,Mgn,Al Mgn-1团簇有类似的结构生长方式.带一个负电和掺杂一个Al原子均能使Mgn团簇的平均结合能增大,稳定性增强.并发现Mgn-(n=2 ～13)团簇在n=4 ,9时比较稳定,在n=11时稳定性较差,与实验结果一致;而等电子的Al Mgn-1团簇在n=4 ,7 ,9时比较稳定.Geometry optimization and frequency analysis of Mgn^-,AlMgn-1（n=2～13） clusters have been studied by using density functional theory（DFT）.The average binding energy,the second-order difference energy and the dissociation energy were calculated.Compared to the lowest energy structures of Mgn clusters,the structures of Mgn^-clusters do not change apparently（except for n=6,8,11）.The doping of Al atom makes the lowest energy structures of Mgn clusters un-remarkable variational,and the growth patterns of AlMgn-1 clusters are similar to that of the Mgn clusters.While adding a negative charge,the doping of one Al atom makes the average binding energy higher and the stability enhanced.For Mgn^-（n=2～13） clusters,Mg4^- and Mg9^- hold relative higher stabilities while Mg11^- holds lower stability,which are in agreement with the available experimental data.However,for the AlMgn-1 clusters having the same charges as the Mgn^- clusters,AlMg3,AlMg6 and AlMg8 are the most stable clusters.

关 键 词：密度泛函理论 最低能量结构Mgn^- AlMgn-1团簇 稳定性 

分 类 号：O641[理学—物理化学]