[SiMo_4^(V)Mo_8^(VI)O_(40)]^(8-)及其钒取代杂多阴离子的量子化学研究

Studies on [SiMo_4^(V)Mo_8^(VI)O_(40)]^(8-) and Its Vanadium Substituted Heteropolyanions by Quantum Chemistry

采用SCC-DV－Xα方法对α－Keggin结构四电子还原态杂多蓝阴离子[SiMo4VMo8VIO40]8-及其四钒取代阴离子[SiMo4VMo8VIO40]8-进行了量子化学计算研究，获得了轨道能级、费米能级、各原子价电子布居，自由价，总态密度图和自洽原子轨道布居等信息．分析表明杂多阴离子中Oc和Od的成键能力较强，化学活性较大，这有力支持了实验结果．体系各原子上的电子是以离域形式存在，构成三金属簇的八面体结构都发生一定程度畸变，中心的硅氧四面体发生畸变程度很小，但整体仍保持α-Keggin结构．

SCC-DV-Xa method has been used for calculating four-electron heteropoly blue anion[SiMo4Mo8O40]8 and its vanadium Substituted heteropolyanion [SiMo4Mo8O40]8 with α-keggin structure. The frontier molecular orbitals, orbital energies, fermi levels, the occupation numbers of basis sets, free valence, Self-consistent atom orbital populations and the figure of total density of states are obstained. It is indicated that Oc and Od have more strong Potential to form bonds. The electrons are delocalised among all of atoms and the trimetal units are distorted partly, the central part is distorted slightly, but the total is still keeping α-Keggin structure.