摘要
采用密度泛函理论(DFT)中的杂化密度泛函B3LYP方法在Lanl2dz基组水平上对PtnNim(n+m=6,n、m≠0)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,并对其能量、热力学性质、核独立化学位移、光谱和极化率进行了理论研究.研究结果表明,PtNi5、Pt2Ni4和Pt3Ni3团簇的基态结构都为四角双锥结构,Pt4Ni2和Pt5Ni团簇的基态结构分别是戴帽三角双锥和三角锥戴四边形结构;PtnNim团簇的生成焓都为负值,表明团簇在热力学上是稳定的;由核独立化学位移值可得,PtNi5团簇具有反芳香性,Pt2Ni4和Pt5Ni团簇具有芳香性;从光谱分析来看,Pt3Ni3团簇的IR较强吸收峰的个数最多,PtNi5团簇IR和Raman、Pt2Ni4团簇的IR、Pt3Ni3和Pt4Ni2团簇的Raman只有一个强吸收峰值,Pt5Ni团簇的峰值只出现在频率较大的位置,频率小的位置几乎为零.
All the possible geometrical structures of PtnNim（n＋m=6, n、m≠0）clusters are optimized with a hybrid Density functional theory （B3LYP） at Lanl2dz level. For the most stable structures, the energy,thermodynamic properties,Nucleus Independent Chemical Shifts （NICS）,spectrum and polarizability are studied.The calculated results show： the ground state structures of PtNi5, Pt2Ni4 and Pt3Ni3 clusters are quadrangular bi-pyramid, and Pt4Ni2 and Pt5Ni clusters are triangular bi-pyramid with hat and triangular pyramid with quadrilateral, respectively. From the point of view of thermodynamics, PtnNim clusters are stable because of the negative enthalpy of formation; the positive NICS of PtNi5 clusters show anti-aromaticity, The negative NICS of Pt2Ni4 and Pt5Ni clusters show aromaticity. The number of the IR absorption peak of Pt3Ni3 is the most. The IR and raman absorption peak of PtNi5 , IR of Pt2Ni4, Raman of Pt3Ni3 and Pt4Ni2 have only one. The absorption peak of Pt5Ni appears in the bigger frequencies only, and is zero almost in the small frequencies.
出处
《光子学报》
EI
CAS
CSCD
北大核心
2009年第12期3109-3115,共7页
Acta Photonica Sinica
基金
江苏省高校基金(2005QT010J)资助
关键词
PtnNim团簇
光谱
极化率
密度泛函理论
PtnNim clusters
Spectrum
Polarizability
Density functional theory （DFT）
