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In this paper, based on the first principles of the density functional theory quantum chemical methods detailed study of the doping of Tb atom and several other transition metal atoms (Y, Pd, La, Yb, Lu) Si_n clusters. Mainly discuss the geometric structure of the clusters, electronic, and magnetic properties. Its main contents are as follows: On the one hand, from the first principle, the use of Dmol ~ 3 software in the generalized gradient approximation (GGA), a detailed study Si_n (n = 3-14) clusters of growth mode and doping TbSi_n some of the characteristics of the clusters. The results show that: n = 4 start, Si_n clusters presents a three-dimensional (3D) structure, and as the cluster size increases tend to form a close-packed structure. Clusters average binding energy, dissociation energy and the energy gap (HOMO-LOMO) calculation and analysis that greatly enhances the stability of the clusters Si_n Tb atom doping Si_n. Mulliken charge analysis found that for TbSi_n clusters charge always from the the Tb atom to each Si atom transfer. In addition, we have also analyzed the TB atoms doped Si_n clusters before and after magnetic moment change, and metal atom doped Si_n magnetic clusters have been significantly increased, and these magnetic moments localized around Tb atom, mainly by the f orbital electron contribution, show that f orbital electrons exhibit the great locality and does not participate in the chemical bonding. The partial density analysis TbSi10 clusters, for example, the presence of strong sp hybridization between Tb atoms and Si atoms. The stable TbSi_n clusters in the semiconductor magnetic materials have broad application prospects. On the other hand, we also chose several different valence electron configuration of the metal atoms (Y, Pd, La, Yb, Lu) as a dopant atoms using density functional theory Dmol ~ 3 package under generalized gradient approximation (GGA) method, TMSi_n (TM = Y, Pd, La, Yb, Lu) ground state structure and electronic properties of clusters. By calculation and discussion: In n ≤ 10, all doped metal atoms are located outside the Si atoms, the specific location is not the same. From n = 11 start, as the cluster size increases, the metal atom gradually into Si_n clusters within framework gradually tends clathrate structure is formed. Especially metal atom Pd at n = 11 earlier caught Si_n Clusters center to form a cage-like ground state structure. N = 16, we studied all metal atoms are completely caught up in the center of the icosahedral clusters Si_n. In addition, we also calculated the magnetic clusters results showed little: TMSi_n clusters of magnetic and starting from n = 6, clusters TMSi_n the magnetic moment of occurrence of \Analysis from the layout of the Mulliken charge outside addition to PdSi_n clusters, the clusters of the charge transfer direction changes with increasing cluster size, clusters orbit
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