On the stability of "non-magic" endohedrally doped Si clusters: a first-principles sampling study of MSi16(+) (M = Ti,V,Cr).
On the stability of "non-magic" endohedrally doped Si clusters: a first-principles sampling study of MSi16(+) (M = Ti,V,Cr).
复制标题
DOI：
10.1063/1.3604565
复制
发表时间：
2011-04
期刊：
影响因子：
--
通讯作者：
D. Palagin;Matthias Gramzow;K. Reuter
中科院分区：
文献类型：
--
作者：
D. Palagin;Matthias Gramzow;K. Reuter
用密度泛函理论研究了含Ti、V或Cr掺杂原子的Si（16）（+）团簇的几何结构和电子结构。通过无偏全局几何优化的基础上的盆跳跃的方法，我们确认，一个弗兰克-卡斯珀多面体，在中心的金属原子，代表基态异构体的所有三个系统。因此，即使在流行的球势模型中只有VSi（16）（+）实现电子壳层闭合，内笼几何形状也是稳定的。我们的电子结构的分析跟踪这种减少的作用壳封闭的稳定回到适应能力的金属-Si键合，这是一个复杂的杂交比原来提出的仅仅是正式的电荷转移的结果。由此产生的金属-Si键的灵活性也可以帮助稳定“非魔法”笼-掺杂剂组合，这表明更广泛的材料最终可以被铸造成这种用于簇组装材料的有用几何形状。
Density-functional theory is used to study the geometric and electronic structure of cationic Si(16)(+) clusters with a Ti, V, or Cr dopant atom. Through unbiased global geometry optimization based on the basin-hopping approach, we confirm that a Frank-Kasper polyhedron, with the metal atom at the center, represents the ground-state isomer for all three systems. The endohedral cage geometry is thus stabilized even though only VSi(16)(+) achieves electronic shell closure within the prevalent spherical potential model. Our analysis of the electronic structure traces this diminished role of shell closure for the stabilization back to the adaptive capability of the metal-Si bonding, which is more the result of a complex hybridization than the originally proposed mere formal charge transfer. The resulting flexibility of the metal-Si bond can also help to stabilize "non-magic" cage-dopant combinations, which suggests that a wider range of materials may eventually be cast into this useful geometry for cluster-assembled materials.