金属硼球烯VB_(40)^(-)团簇的结构、稳定性、光谱和键合:粒子群优化算法结合密度泛函理论研究

Structure,stability,spectra,and bonding of metalloborospherene VB_(40)^(-) clusters:A density functional study combining the particle swarm optimization algorithm

本文通过粒子群优化算法结合量子化学计算,对V掺杂硼团簇VB_(40)^(-)的各种候选结构进行了全局预测.对于VB_(40)^(-)团簇,我们预测2个能量最低的结构(结构Ⅰ和Ⅱ)为内嵌式金属硼球烯.结构Ⅰ具有VB_(40)^(-)对称性,继承了B_(40)(D_(2d)对称性)的笼形结构,硼与钒的配位数为16,而结构Ⅱ之前未见报道.值得注意的是,新发现的结构Ⅱ有Cs对称性,有最高配位数,为20.基于这2种结构,本文利用分子轨道、Wiberg键级和电子局域函数分析了其电子性质.适应性自然密度划分与化学键分析表明,VB_(40)^(-)团簇(VB_(40)^(-)对称性)的σ键和π键较好地继承了B_(40)(D_(2d)对称性)键的特征.此外,我们还模拟了光电子能谱、红外光谱、拉曼光谱和紫外可见光光谱,以便于后期的实验表征.

Various candidate structures of V-doped boron clusters VB_(40)^(-) are predicted globally via the particle swarm optimization algorithm combining quantum chemistry calculations.For the VB_(40)^(-) clusters,the two lowest energy structures(C_(2v) structureⅠand Cs structureⅡ)are predicted to be endohedral metalloborospherenes.StructureⅠis well inherited in the cage geometry of D_(2d) B_(40) with the vanadium coordination number of sixteen,while structureⅡhas not been reported before.Notably,the newly discovered structureⅡhas 20-fold coordination with the largest coordination state.Based on these two structures,electronic properties are analyzed by molecular orbitals,Wiberg bond order and electron localization function.The adaptive natural density partitioning and chemical bond analysis indicate that both theσandπbonds of the C_(2v) VB_(40)^(-) cluster are well inherited in the D_(2d) B_(40) bonding characteristics.In addition,photoelectron spectroscopy,infrared,Raman,and UV-Vis spectra are simulated to facilitate future experimental characterizations.