Density functional study on structures, stabilities, and electronic properties of size-selected Pd n Si q (n = 1–7 and q = 0, +1, −1) clusters

Abstract

The density functional theory (DFT) calculations within the framework of generalized gradient approximation have been employed to systematically investigate the geometrical structures, stabilities, and electronic properties of PdnSiq (n = 1–7 and q = 0, +1, −1) clusters and compared them with the pure \({\text{Pd}}_{n + 1}^{q}\) (n = 1–7 and q = 0, +1, −1) clusters for illustrating the effect of doping Si atom into palladium nanoclusters. The most stable configurations adopt a three-dimensional structure for both pure and Si-doped palladium clusters at n = 3–7. As a result of doping, the PdnSi clusters adopt different geometries as compared to that of Pdn+1. A careful analysis of the binding energies per atom, fragmentation energies, second-order difference of energies, and HOMO–LUMO energy gaps as a function of cluster size shows that the clusters \({\text{Pd}}_{4}^{ + }\), \({\text{Pd}}_{4}\), \({\text{Pd}}_{8}^{ - }\), \({\text{Pd}}_{5} {\text{Si}}^{0, + , - }\), and \({\text{Pd}}_{7} {\text{Si}}^{0, + , - }\) possess relatively higher stability. There is enhancement in the stabilities of palladium frameworks due to doping with an impurity atom. In addition, the charge transfer has been analyzed to understand the effect of doped atom and compared further.