杂多阴离子[P_2Mo_5O_(23)]^(6-)的稳定结构和电子性质DFT比较研究

A DFT study on electronic properties and structures of [P_2Mo_5O_(23)]^(6-)heteropolanions

运用量子化学密度泛函理论(DFT)的BP86,BP91,BLYP方法系统优化[P2Mo5O23]6-杂多阴离子几何结构,并对该杂多阴离子电子性质进行分析比较.计算结果表明:三种方法几何优化结果与实验数据均具有一致性,其中BP86方法计算结果与实验值最接近;最高占有轨道主要分布在与P原子相连的端氧和P—O—Mo键桥氧的p轨道上,最低空轨道主要集中在Mo原子的d轨道和部分O原子的p轨道上;所有Mo原子和P原子的正电荷都小于正常的氧化态,所有O原子的负电荷小于-2.

Calculational based on density functional theory(DFT)have been carried out to investigation the electronic properties and structure of [P_2Mo_5O_(23)]^(6-)(M=Mo,W)heteropolnions with BP86,BP91,and BLYP methods.The results show that good computational-experimental agreement for the geometrized parameters has been obtained for[P_2Mo_5O_(23)]^(6-).But BP86 method is the best.The electronic structure of the anions has been probed with molecular orbital and bonding energy approaches.The results have indicated that the highest occupied molecular orbital(HOMO)localized over the p orbital of the oxygen atoms,the lowest unoccupied molecular orbitals(LUMO)localized over the d orbitals of the Mo atoms and p orbitals of the oxygen atoms.The Mulliken charge analysis show that mo atoms and P atoms obtained electrons form adjacent oxygen atoms.Metal charges are considerably smaller than the formal oxidation states.