W_nNi_m(n+m=8)团簇轨道能级与芳香性的理论研究  

Theoretical Study of Molecular Orbital Energy Levels and Aromaticity of W_nNi_m(n+m=8)clusters

作　　者：张秀荣[1] 李扬[1] 尹琳[1] 

机构地区：[1]江苏科技大学数理学院,江苏镇江212003

出　　处：《计算物理》2012年第6期913-920,共8页Chinese Journal of Computational Physics

基　　金：国家自然科学基金(51072072);江苏省自然科学基金(BK2010343)资助项目

摘　　要：用密度泛函理论(DFT)中的b3lyp方法,在Lanl2dz基组水平上对WnNim(n+m=8)团簇的各种可能构型进行几何参数全优化,得到它们的基态构型;并对基态构型的轨道能级分布、能隙、HOMO、LUMO能级、芳香性和热力学性质进行分析,结果表明:团簇W5Ni3和W6Ni2的Alpha轨道和Beta轨道是完全简并的,所有电子都是严格两两配对的;团簇W2Ni6能隙最小,化学活性最强,组成前线轨道的成分基本相同;W6Ni2能隙最大,化学活性最弱;团簇W1Ni7,W5Ni3,W6Ni2,W7Ni1具有芳香性,W2Ni6具有反芳香性;团簇的生成焓都是负值,为放热反应,热力学上是稳定的.Possible equilibrium geometries of WnNim（n＋m=8） clusters are optimized with density functional theory at B3LYP/LANL2DZ level.For ground state structures,molecular orbital energy level,HOMO level,LUMO level,aromaticity and thermodynamics are analyzed.It shows that molecular orbits between Alpha and Beta in clusters W5Ni3 and W6Ni2 are completely degenerate,and all electrons are strictly paired.W2Ni6 cluster,with low energy gap,has strong chemical activity.Its component for frontier orbital are basically the same.W6Ni2 cluster,with high energy gap,has weak chemical activity;Clusters W1Ni7,W5Ni3,W6Ni2,W7Ni1 have aromaticity,while W2Ni6 cluster has antiaromaticity.Formation enthalpy of all clusters WnNim（n＋m=8） are negative.They are stable on thermodynamics.

关 键 词：WnNim(n+m=8)团簇 轨道能级 芳香性 密度泛函理论 

分 类 号：O641[理学—物理化学]