Structures of gas-phase Ag-Pd nanoclusters: a computational study.

Gas-phase Ag-Pd clusters in the size range of 38-100 atoms are studied via a combined density-functional/empirical-potential (DF-EP) approach. Many-body EPs describing Pd-Pd, Ag-Ag, and Ag-Pd interactions are reparametrized and used in thorough global optimization searches at sizes N=38, 60, and 100 and compositions 25%, 50%, and 75%. The results are analyzed in terms of structural families, whose lowest-energy isomers are reoptimized at the DF level to investigate the crossover among structural motifs.

Structures of metal nanoparticles adsorbed on MgO(001). II. Pt and Pd.

The structure of metal clusters on MgO(001) is searched for by different computational methods. For sizes N < or = 200, a global optimization basin-hopping algorithm is employed, whereas for larger sizes the most significant structural motifs are compared at magic sizes. This paper is focused on Pt and Pd/MgO(001), which present a non-negligible mismatch between the nearest-neighbor distance in the metal and the oxygen-oxygen distance in the substrate.

Structures of metal nanoparticles adsorbed on MgO(001). I. Ag and Au.

The structure of metal clusters supported on a MgO(001) substrate is investigated by a computational approach, with the aim to locate stable structural motifs and possible transition sizes between different epitaxies. Metal-metal interactions are modeled by a second-moment approximation tight-binding potential, while metal-oxide interactions are modeled by an analytic function fitted to first-principles calculations. Global optimization techniques are used to search for the most stable structural motifs at small sizes (N < or = 200), while at larger sizes different structural motifs are compared at geometric magic numbers for clusters up to several thousand atoms.