Assessing Covalency in Cerium and Uranium Hexachlorides: A Correlated Wavefunction and Density Functional Theory Study
Assessing Covalency in Cerium and Uranium Hexachlorides: A Correlated Wavefunction and Density Functional Theory Study
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DOI：
10.3390/inorganics3040482
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发表时间：
2015-12-01
期刊：
影响因子：
2.9
通讯作者：
Kerridge, Andrew
中科院分区：
文献类型：
--
作者：
Beekmeyer, Reece;Kerridge, Andrew
在相关波函数和密度泛函（DFT）理论水平上对一系列铀和铈六氯化物在各种氧化态下的电子结构进行了评估。根据最近对四价六氯化铈共价性的实验观察，采用基于分子中原子量子理论（QTAIM）的拓扑和积分分析方法研究了四价六氯化铈的成键特征。该分析表明，M-Cl共价性强烈依赖于氧化态，在较高氧化态络合物中发现更大的共价性。M-Cl离域指数的比较显示了相关波函数和DFT衍生值之间的差异。这些离域指数的分解表明，这种差异的起源在于ungerade的贡献与f-流形，我们建议是由于自相互作用的错误固有的DFT为基础的方法。通过本研究中使用的所有措施，发现在相同氧化态的U和Ce的络合物之间的共价性极其相似的水平。
The electronic structure of a series of uranium and cerium hexachlorides in a variety of oxidation states was evaluated at both the correlated wavefunction and density functional (DFT) levels of theory. Following recent experimental observations of covalency in tetravalent cerium hexachlorides, bonding character was studied using topological and integrated analysis based on the quantum theory of atoms in molecules (QTAIM). This analysis revealed that M-Cl covalency was strongly dependent on oxidation state, with greater covalency found in higher oxidation state complexes. Comparison of M-Cl delocalisation indices revealed a discrepancy between correlated wavefunction and DFT-derived values. Decomposition of these delocalisation indices demonstrated that the origin of this discrepancy lay in ungerade contributions associated with the f-manifold which we suggest is due to self-interaction error inherent to DFT-based methods. By all measures used in this study, extremely similar levels of covalency between complexes of U and Ce in the same oxidation state was found.