Insights into the geometries, electronic and magnetic properties of neutral and charged palladium clusters

Abstract

We performed an unbiased structure search for low-lying energetic minima of neutral and charged palladium PdnQ (n = 2–20, Q = 0, + 1 and –1) clusters using CALYPSO method in combination with density functional theory (DFT) calculations. The main candidates for the lowest energy neutral, cationic and anionic clusters are identified, and several new candidate structures for the cationic and anionic ground states are obtained. It is found that the ground state structures of small palladium clusters are more sensitive to the charge states. For the medium size Pdn0/+/– (n = 16–20) clusters, a fcc-like growth behavior is found. The structural transition from bilayer-like structures to cage-like structures is likely to occur at n = 14 for the neutral and cationic clusters. In contrast, for the anionic counterparts, the structural transition occurs at Pd13–. The photoelectron spectra (PES) of palladium clusters are simulated based on the time-dependent density functional theory (TD-DFT) method and compared with the experimental data. The good agreement between the experimental PES and simulated spectra provides us unequivocal structural information to fully solve the global minimum structures, allowing for new molecular insights into the chemical interactions in the Pd cages.

Application of a parallel genetic algorithm to the global optimization of medium-sized Au–Pd sub-nanometre clusters

“…The GM for Pd 12 has a (C 1 ) buckled mono-planar (BMP) structure, which is similar to that observed recently by Xing and co-workers [32]. The GM of Pd 15 is a buckled biplanar (BBP) structure.…”

“…The GM of Pd 15 is a buckled biplanar (BBP) structure. In the case of Pd N clusters, N = 16-18 atom, the global minima are found to be pseudo-spherical filled cage structures and agree with the fcc-like growth pathway observed previously for 16-20 atoms [14,32,70].…”

“…Hence, a combination of experimental techniques with theoretical calculations has been used effectively: for example, Fielicke and co-workers [28] reported the gas-phase structures of neutral Au 7 , Au 19 , and Au 20 clusters tagged with Kr atoms. The case of Pd is similar as, unlike the smaller Pd clusters, studies of medium sized clusters are relatively few and are the object of some controversy in terms of identifying the structural characteristics [32]. Turning our attention to medium-sized Au-Pd nanoalloys, a comprehensive study of structural motifs for all compositions have, to our knowledge, not been investigated before.…”

Geometrical Structures and Electronic Properties of Ga6 and Ga5X (X = B, C, N, O, F, Al, Si, P, S, Cl) Clusters

“…The algorithm can predict stable structures depending only on the chemical composition. It has been successful in correctly predicting structures for various systems [31,32,33,34]. The optimized structures obtained from particle swarm optimization (PSO) are taken as the initial structures for further simulation by the DFT method.…”

First-principle study of structural, electronic and magnetic properties of (FeC)n (n = 1–8) and (FeC)8TM (TM = V, Cr, Mn and Co) clusters

“…This combined CALYPSO/DFT computational approach has been previously used to search for low-lying palladium clusters, copper clusters, ruthenium doped germanium clusters et al . 37–40 . Based on the lowest energy structure, the electronic and magnetic properties are investigated in detail as the cluster size increase.…”