氨团簇(NH3)n(n=2～8)结构的密度泛函理论研究  

Application of density functional theory for the study of ammonia clusters from n=2 to 8

作　　者：刘存海[1] 孔祥和[1] 孙志青[1] 乔光[2] 张树东[1] 

机构地区：[1]曲阜师范大学物理工程学院,曲阜273165 [2]西华师范大学物理工程学院,南充637002

出　　处：《原子与分子物理学报》2008年第2期357-362,共6页Journal of Atomic and Molecular Physics

摘　　要：本文应用密度泛函理论(DFT)的B3LYP方法,在6-31G(d)和6-31++G(d)基组水平上对氨团簇氢键体系进行了研究,计算得到了氨团簇(NH3)n(n=2～8)的各种稳定构型及对应的能量和团簇束缚能.分析发现,在各类尺寸中以单环结构最为稳定,而相同尺寸的异构体之间团簇束缚能越大越稳定.最后利用二阶差分理论讨论了不同尺寸氨团簇中最稳定结构的生长规律,结果表明n=5,7时的结构最为稳定,具有明显的幻数特征,n=6,8时的团簇结构最不稳定,而在n=2～5之间,随着n的增大团簇的稳定性也在逐步增强.In this paper,the system of hydrogen-bonded ammonia clusters is studied at the 6-31G（d） and 6-31＋＋G（d） basis sets level,using the B3LYP method of density functional theory.Through calculation,different structures,energies and binding energies of various ammonia clusters are gained.The structure with only a ring is the most stable one in each cluster size.For the same cluster size,the greater the binding energy is,the more stable the cluster is.Finally,the second differential theory is used to discuss the growth law of the most stable ammonia clusters in different cluster sizes.The result shows that the clusters for n=5 and n=7 are the most stable ones and have the features of magic number.But the stability of the clusters is worst for n=6 and n=8,and the stability of the clusters from n=2 to n=5 is gradually increasing with the increasing of cluster size n.

关 键 词：密度泛函理论 团簇 二阶差分 束缚能 

分 类 号：O641[理学—物理化学]