Tam Nguyen Minh, Duong Long Van, Cuong Ngo Tuan, Nguyen Minh Tho
Computational Chemistry Research Group, Ton Duc Thang University Ho Chi Minh City Vietnam
Faculty of Applied Sciences, Ton Duc Thang University Ho Chi Minh City Vietnam.
RSC Adv. 2019 Aug 30;9(47):27208-27223. doi: 10.1039/c9ra04004h. eCollection 2019 Aug 29.
Structures of the binary Al Si clusters in both neutral and cationic states were investigated using DFT and TD-DFT (B3LYP/6-311+G(d)) and (U)CCSD(T)/cc-pvTZ calculations. Silicon-doped aluminum clusters are characterized by low spin ground states. For small sizes, the Si dopant prefers to be located at vertices having many edges. For larger sizes, the Si atom prefers to be endohedrally doped inside an Al cage. Relative stability, adiabatic ionization energy and dissociation energies of each cluster size were evaluated. A characteristic of most Si doped Al clusters is the energetic degeneracy of two lowest-lying isomers. Calculated results confirm the high stability of the sizes AlSi, AlSi and AlSi as "magic" clusters, that exhibit 20 or 40 shell electrons and are thermodynamically more stable as compared to their neighbors. Electronic absorption spectra of isoelectronic magic clusters Al , AlSi, and AlSi that have two pronounced bands corresponding to blue and violet lights, have been rationalized by using the electron shell model. The magnetically included ring current density (MICD) analyses suggest that they are also aromatic structures as a result of the "magic" 40 shell electrons.
使用密度泛函理论（DFT）和含时密度泛函理论（TD-DFT）（B3LYP/6-311+G(d)）以及（U）耦合簇理论（CCSD(T)/cc-pvTZ）计算，研究了中性和阳离子态的二元铝硅团簇的结构。硅掺杂的铝团簇具有低自旋基态的特征。对于小尺寸团簇，硅掺杂剂倾向于位于具有多条边的顶点处。对于较大尺寸团簇，硅原子倾向于被包埋在铝笼内部。评估了每个团簇尺寸的相对稳定性、绝热电离能和解离能。大多数硅掺杂铝团簇的一个特征是两个最低能量异构体的能量简并。计算结果证实了尺寸为AlSi、AlSi和AlSi的“幻数”团簇具有高稳定性，它们表现出20或40个壳层电子，并且与相邻团簇相比在热力学上更稳定。通过使用电子壳层模型，对具有对应于蓝光和紫光的两个明显谱带的等电子幻数团簇Al、AlSi和AlSi的电子吸收光谱进行了合理解释。磁包含环电流密度（MICD）分析表明，由于“幻数”40个壳层电子，它们也是芳香结构。
