用basin-hopping算法结合密度泛函PBE方法系统搜索了Au5~25Pd团簇的全局稳定结构,并对团簇几何结构,稳定性,Fermi能级,化学硬度和前线轨道进行了分析。计算结果表明,Au5Pd,Au7Pd和Au11Pd团簇为平面结构,其他团簇均为立体结构,与相同原子数纯金团簇结构类似。所有团簇中,Pd原子均位于配位数较高位置。团簇平均结合能随金原子数增大而逐渐增大,并有收敛到某点的趋势。偶数金原子团簇较相邻的奇数金原子团簇稳定。团簇的Fermi能级随团簇增大呈奇偶振荡,偶数金原子团簇的Fermi能级较相邻奇数金原子团簇的低,与金团簇Fermi能级变化类似。Au7Pd,Au12Pd,Au16Pd和Au18Pd团簇化学活性较高。Au5~19Pd团簇中Pd原子优先与CO,烯烃,炔烃等分子形成配位键。CO等小分子仍然吸附到Au20~25Pd团簇的顶点或面中心的金原子。
The global minima of Au5~25 Pd clusters were systematically searched by means of the basin-hopping algorithm in combi-nation with PBE functional of density functional theory. The structure,relative stability,Fermi level,chemical hardness,and frontier molecular orbitals of these clusters were investigated at the PBE/DND level. The computational results indicated that Au5 Pd, Au7 Pd,and Au11 Pd clusters were planar structures;the other clusters were three-dimensional structures. The structures of Pd-doped gold clusters were similar with the same-sized gold clusters. The average binding energies and Fermi levels were similar to those of the pure gold clusters,demonstrating an odd-even oscillation. The chemical activities of Au7 Pd,Au12 Pd,Au16 Pd,and Au18 Pd clus-ters were larger than those of the others. The small molecules( such as CO,alkyne,alkene et al) were preferred to adsorb on the Pd atom of Au5~19 Pd clusters,while they were adsorbed on the surface gold atom of Au20~25 Pd cluster
