文献类型：期刊文献

英文题名：Computational investigation of Ti Sin (n=2-15) clusters by the density-functional theory

作者：Guo, Ling-Ju[1]; Liu, Xia[1]; Zhao, Gao-Feng[1]; Luo, You-Hua[1,2]

机构：[1] School of Physics and Electronics, Henan University, Kaifeng 475001, China; [2] Department of Physics, East China University of Science and Technology, Shanghai 200237, China

年份：2007

卷号：126

期号：23

外文期刊名：Journal of Chemical Physics

收录：EI(收录号：20073110730214)

语种：英文

外文关键词：Computation theory - Density functional theory - Encapsulation - Molecular dynamics - Nanoclusters

摘要：The geometries, stabilities, and electronic properties of Ti Sin (n=2-15) clusters with different spin configurations have been systematically investigated by using density-functional theory approach at B3LYP/LanL2DZ level. According to the optimum Ti Sin clusters, the equilibrium site of Ti atom gradually moves from convex to surface, and to a concave site as the number of Si atom increases from 2 to 15. When n=12, the Ti atom in Ti Si12 completely falls into the center of the Si outer frame, forming metal-encapsulated Si cages, which can be explained by using 16-electron rule. On the basis of the optimized geometries, various energetic properties are calculated for the most stable isomers of Ti Sin clusters, including the average binding energy, the highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO-LUMO) gap, fragmentation energy, and the second-order difference of energy. It is found that at size n=6,8,12 the clusters are more stable than neighboring ones. According to the Mulliken charge population analysis, charges always transfer from Si atoms to Ti atom. Furthermore, the HOMO-LUMO gaps of the most stable Ti Sin clusters are usually smaller than those of Sin clusters. ? 2007 American Institute of Physics.