W_n Ni_m(n+m≤7;m=1,2)团簇电子结构与光谱性质的理论研究  

The theory study of electronic structures and spectram properties of W_n Ni_m (n+m≤7; m=1,2) clusters

作　　者：张秀荣[1] 高从花[2] 吴礼清[2] 唐会帅[2] 

机构地区：[1]江苏科技大学高等教育研究所,镇江212003 [2]江苏科技大学材料科学与工程学院,镇江212003

出　　处：《物理学报》2010年第8期5429-5438,共10页Acta Physica Sinica

基　　金：江苏省普通高校研究生科研创新计划(批准号:CX09S_002Z)资助的课题~~

摘　　要：采用密度泛函理论(DFT)中的B3PW91方法在LANL2DZ基组水平上对WnNim(n+m≤7;m=1,2)团簇的各种可能构型进行了几何结构优化,得出了它们的基态构型,并对其NBO、振动频率、光谱和极化率进行了理论研究.研究结果表明:W,Ni原子内部杂化现象较强,而在W-Ni原子之间杂化较弱;在W和Ni相互作用形成合金团簇的过程中,发生原子间的电荷转移,使得合金团簇中大多数Ni原子带正电荷W原子带负电荷;从光学上分析显示,W6Ni团簇的IR和Raman谱中的振动峰最多,W5Ni2的IR和Raman谱中的振动峰最强,W2Ni的IR谱中只有一个较强峰值;WnNim(n+m≤7;m=1,2)团簇中原子间的成键相互作用随W成分的增加而增强.Possible geometrical structures of WnNim（n ＋ m≤7; m = 1,2） clusters have been optimized by using the density functional theory （B3PW91） at the LANL2DZ level. For the ground state structures,the NBO,vibration frequencies, spectrum and polarizability are studied. The calculated results show： the hybrid phenomenon is very strong within W and Ni atoms,while weak in the W-Ni atoms. In the process of forming alloy clusters,the charge transfer happens owing to the interaction of W and Ni so that most of Ni atom is positive and while W atom is negative. The optical properties indicated, the number of the vibrational peak is the most in the IR and Raman of W6Ni cluster,the IR and raman absorption peak of W5Ni2 is the strongest and the IR absorption peak of W2Ni has only one; the bonding between atoms shows stronger with the increasing of W content in the WnNim（n ＋ m≤7; m = 1,2） clusters.

关 键 词：WnNim(n+m≤7 m=1 2)团簇 电子结构 光谱性质 密度泛函理论 

分 类 号：O481[理学—固体物理]