Theoretical insight on the structural and electronic properties of (PdH)N (N = 10–35) clusters

The structure and electronic properties of the (PdH)N (N = 10–35) clusters were investigated by combining the artificial bee colony algorithm with density functional theory (DFT) calculations. Structure analysis indicates that (PdH)N clusters tend to compose the spherical disordered geometry with the hydrogen atoms generally distribute on the surface in the formation of twofold bridge or threefold hollow sites. The binding energy calculation demonstrated that the formation of (PdH)N clusters is thermodynamic feasible, and the stability of clusters shows an upward trend with the size increasing. Detail structural information show that the bond length of Pd–Pd stretch in the clusters compare with pure Pd bulk since the insertion of H atoms. With respect to the electronic properties, Bader charge analysis revealed the overall trends of charge transfer from Pd to H atoms. The density of states identified the major bonding area of Pd–Pd and Pd-H, as well as the non-magnetic or weakly magnetic characteristics of (PdH)N clusters. Detailed bonding analysis has conducted to (PdH)35 cluster to verify the difference of interaction between Pd and various H atoms. The relationship between inverse projected crystal orbital Hamilton population (-IpCOHP) and Pd-H bond length shows that the bond strength of Pd-H interaction is strongly associated with their structural properties in medium-sized clusters.