Shakerzadeh Ehsan, Duong Long Van, Pham-Ho My Phuong, Tahmasebi Elham, Nguyen Minh Tho
Chemistry Department, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Institute for Computational Science and Technology (ICST), Ho Chi Minh City, Vietnam and Department of Chemistry, Faculty of Natural Sciences, Quy Nhon University, Quy Nhon City, Vietnam.
Phys Chem Chem Phys. 2020 Jul 8;22(26):15013-15021. doi: 10.1039/d0cp02046j.
Systematic density functional theory (DFT) calculations using the TPSSh functional and the def2-TZVP basis set were carried out to identify the global energy minimum structure of the Li2FeB14 cluster. Keeping the double ring tubular shape of FeB14, capping of two Li atoms leads to a teetotum form at a low spin state, in which the Fe atom is endohedrally covered by two B7 strings, and both Li atoms are attached to Fe along the C7 axis at both sides. Calculated results show that strong electrostatic interactions between 2Li+ and Fe2- arising from Li electron transfer upon doping particularly provide a key driving force for stabilizing this charge-transfer structure. The bonding pattern of the teetotum can be understood from the hollow cylinder model (HCM). TD-DFT calculations demonstrate that this cluster can also be regarded as a useful material for transparent optoelectronic devices. Furthermore, the Li2FeB14 superatom can be used as a building block for making boron-based nanowires with metallic character. Replacement of Li atoms by Mg atoms was also found to lead to nanowires.
使用TPSSh泛函和def2-TZVP基组进行了系统的密度泛函理论（DFT）计算，以确定Li2FeB14团簇的全局能量最低结构。保持FeB14的双环管状结构，两个Li原子的封端导致在低自旋态下形成陀螺状结构，其中Fe原子被两个B7链内包，且两个Li原子都沿C7轴在两侧与Fe相连。计算结果表明，掺杂时Li电子转移产生的2Li+和Fe2-之间的强静电相互作用特别为稳定这种电荷转移结构提供了关键驱动力。陀螺状结构的键合模式可以从空心圆柱模型（HCM）来理解。含时密度泛函理论（TD-DFT）计算表明，该团簇也可被视为一种用于透明光电器件的有用材料。此外，Li2FeB14超原子可作为构建具有金属特性的硼基纳米线的基本单元。还发现用Mg原子取代Li原子会导致形成纳米线。
