The connection of atomic clusters has been investigated using molecular-dynamics simulation to explain the splitting of the second peak of the pair-distribution function in amorphous alloys. It is found that the unevenness of the connecting style of atomic clusters results in the splitting of the second peak and the two subpeaks is caused by a three-atom-shared connection and a one-atom-shared connection between atomic clusters. The underlying reason is that metallic glasses have higher density than liquid alloys and a different connecting style of atomic clusters from crystals.

In this paper, the structural transitions of the rapidly cooled Ni nanomaterial under different pressures were studied by using molecular dynamics simulation. The work gives the structural properties, including the potential energy, pair-correlation function and Honeycutt-Andersen (HA) and Voronoi indices. This pair-correlation function of liquid Ni agrees well with the experimental results. The local structures are characterized by Honeycutt-Andersen (HA) indices and Voronoi tessellation. Our results indicate that with the increasing pressure the Ni nanomaterial transformed from the disordered structure to the ordered structure. The icosahedral and defect icosahedral decrease, the hcp-like structure increased at 300 K. These phenomena were shown that the crystalline state is hcp-like local structure.

In bimetallic cluster, research on the frozen structure with the changing concentration plays an important role in exploring new structural materials. This paper studies the freezing processes of (AgCu)309clusters with different Ag concentrations. The results indicated that the structural transformation was strongly related to concentration. It was found that the frozen structures were changed form icosahedron, hcp and fcc-hcp with the change of Ag concentration. The frozen structures were formed icosahedral for the clusters with Ag concentration at 10%, 20%, 30%, and the pure Ag309. For the clusters with Ag content at 40%, 50%, 60%, 70%, and 80%, the frozen structures were formed defect icosahedral. It was also found that the frozen structure have hcp character for the pure Cu309cluster. Meanwhile, the frozen structure of (AgCu)309with 90% Ag concentration was formed fcc-hcp structure. The segregation effects of the Ag-Cu are the key reason for the structural transformation.

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