CAJ | 학술논문

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Pt_nNi_m(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,PtNi_5、Pt_2Ni_4和Pt_3Ni_3团簇的基态结构都为四角双锥结构,Pt_4Ni_2和Pt_5Ni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;Pt_nNi_m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,PtNi_5团簇具有反芳香性,Pt_2Ni_4和Pt_5Ni团簇具有芳香性;从光谱分析来看,Pt_3Ni_3团簇的IR较强吸收峰的个数最多,PtNi_5团簇IR和Raman、Pt_2Ni_4团簇的IR、Pt_3Ni_3和Pt_4Ni_2团簇的Raman只有一个强吸收峰值,Pt_5Ni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.
채용밀도범함이론(DFT)중적잡화밀도범함B3LYP방법재Lanl2dz기조수평상대Pt_nNi_m(n+m=6,n、m≠0)단족적각충가능구형진행료궤하결구우화,득출료타문적기태구형,병대기능량、열역학성질、핵독립화학위이、광보화겁화솔진행료이론연구.연구결과표명,PtNi_5、Pt_2Ni_4화Pt_3Ni_3단족적기태결구도위사각쌍추결구,Pt_4Ni_2화Pt_5Ni단족적기태결구분별시대모삼각쌍추화삼각추대사변형결구;Pt_nNi_m단족적생성함도위부치,표명단족재열역학상시은정적;유핵독립화학위이치가득,PtNi_5단족구유반방향성,Pt_2Ni_4화Pt_5Ni단족구유방향성;종광보분석래간,Pt_3Ni_3단족적IR교강흡수봉적개수최다,PtNi_5단족IR화Raman、Pt_2Ni_4단족적IR、Pt_3Ni_3화Pt_4Ni_2단족적Raman지유일개강흡수봉치,Pt_5Ni단족적봉치지출현재빈솔교대적위치,빈솔소적위치궤호위령.
All the possible geometrical structures of Pt_nNi_m(n+m=6,n、m≠0)clusters are optimized with a hybrid Density functional theory (B3LYP) at Lanl2dz level.For the ground state structures,the energy,thermodynamic properties,Nucleus Independent Chemical Shifts (NICS),spectrum and polarizability are studied.The calculated results show that:the ground state structures of PtNi_5,Pt_2Ni_4 and Pt_3Ni_3 clusters are quadrangular bi-pyramid,and Pt_4Ni_2 and Pt_5Ni clusters are triangular bi-pyramid with hat and triangular pyramid with quadrilateral,respectively.From the point of view of thermodynamics,Pt_nNi_m clusters are stable because of the negative enthalpy of formation;the positive NICS of PtNi_5 clusters show anti-aromaticity,the negative NICS of Pt_2Ni_4 and Pt_5Ni clusters show aromaticity.The number of the IR absorption peak of Pt_3Ni_3 is the most.The IR and Raman absorption peak of PtNi_5 ,IR of Pt_2Ni_4,Raman of Pt_3Ni_3 and Pt_4Ni_2 have only one.The absorption peak of Pt_5Ni appears in the bigger frequencies only,and is zero almost in the small frequencies.