| Summary: | 碩士 === 國立中央大學 === 物理研究所 === 91 ===
We present detailed numerical results on the ground state structures of metallic clusters and alloy clusters. The Gupta-like many-body potential is used to account for the interactions between atoms in the cluster. Both the genetic algorithm technique and the basin hopping method have been applied to search for the global energy minima of clusters. The good agreement found in both schemes for the global energy minima gives credence to the optimized energy values obtained. Our calculations for the ground state energies of alkali metallic clusters show regularities in the energy differences, and the cluster growth pattern manifested by this same group of clusters is generally icosahedral which is quite different from the close-packed and decahedral preferentially exhibited by the tetravalent lead clusters. Considering the inherent disparities in the electronic structures and the bulk structures in these metals (body-centered cubic for alkali metals and face-centered cubic for the lead metal), it is not unreasonable to say that the valence electrons do play a subtle role in the conformation of metallic clusters.And last,we introduce a new minimization method which contains all the advantages of the above algorithms,to examine the nanoalloy cluster,Cu-Au for total number N=38.To check all the permutation and the structure variation.In evidence,there exists the most stablize structure in an alloy with total number N=38.Our algorithm also shows the reliability to compete Basin-Hopping and Genetic Algorithm.
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