Pd-Y微团簇的结构与性质研究

Study on the structures and properties of small Pd-Y clusters

在相对论有效原子实势近似下,用密度泛函理论方法,对Pdn(n=2,3,4),Yn(n=2,3,4),PdnY(n=1,2,3,4),PdYn(n=2,3,4),Pd2Yn(n=2,3,4)团簇的各种可能的几何构型进行全优化计算,得到它们的基态结构和光谱性质.结果表明,由于Jahn-Teller效应,Pd4和Y4的基态结构为Cs构型,Pd3和Y3为C2v构型;混合微团簇Pd3Y,Pd4Y,PdY3,PdY4和Pd2Y4基态为Cs构型.最后计算了团簇的能级分布和最高占据轨道与最低空轨道之间的能级间隙,分析了团簇的化学活性.

The possible geometrical and electronic structures of small Pd-Y clusters including Pd-n (n = 2, 3,4), Y-n (n = 2, 3,4) PdYn (n = 2,3,4), PdnY(n = 1, 2,3,4) and Pd2Yn (n = 2,3,4) have been optimized by density functional theory method with a relativistic effective core potential(RECP) using Gaussian 98 code. Due to the Jahn-Teller effect, the ground states of Pd-4 and Y-4 belong to C-s, while the symmetry is C-2v for Pd-3 and Y-3. The ground states of Pd3Y, Pd4Y, PdY3, PdY4 and Pd(2)Y(4)belong to C-s. Finally, the energy level distribution, highest occupied molecular orbit-lowest unoccupied molecular orbit gaps and the chemical activation are investigated.