Babetto Luca, Carlotto Silvia, Carlotto Alice, Rancan Marzio, Bottaro Gregorio, Armelao Lidia, Casarin Maurizio
Dipartimento di Scienze Chimiche, Università degli Studi di Padova, via F. Marzolo 1, 35131 Padova, Italy.
Institute of Condensed Matter Chemistry and Technologies for Energy (ICMATE), National Research Council (CNR), c/o Department of Chemistry, University of Padova, via F. Marzolo 1, 35131 Padova, Italy.
Inorg Chem. 2021 Jan 4;60(1):315-324. doi: 10.1021/acs.inorgchem.0c02956. Epub 2020 Dec 15.
A theoretical protocol combining density functional theory (DFT) and multireference (CAS) calculations is proposed for a Eu complex. In the complex, electronic levels of the central Eu ion are correctly calculated at the CASPT2 level of theory, and the effect of introducing different numbers of states in the configuration interaction matrices is highlighted as well as the shortcomings of DFT methods in the treatment of systems with high spin multiplicity and strong spin-orbit coupling effects. For the D state energy calculation, the inclusion of states with different multiplicity and the number of states considered for each multiplicity are crucial parameters, even if their relative weight is different. Indeed, the addition of triplet and singlets is important, while the number of states is relevant only for the quintets. The herein proposed protocol enables a rigorous, full treatment of Eu complex, which can be easily extended to other Ln ions.
提出了一种结合密度泛函理论（DFT）和多参考（CAS）计算的理论方案用于一种铕配合物。在该配合物中，中心铕离子的电子能级在CASPT2理论水平上得到了正确计算，同时突出了在组态相互作用矩阵中引入不同数量状态的影响以及DFT方法在处理具有高自旋多重度和强自旋 - 轨道耦合效应的体系时的缺点。对于D态能量计算，包含不同多重度的状态以及为每个多重度考虑的状态数量是关键参数，即使它们的相对权重不同。实际上，添加三重态和单重态很重要，而状态数量仅对五重态有影响。本文提出的方案能够对铕配合物进行严格、全面的处理，并且可以很容易地扩展到其他镧系离子。
