Khanna Vaibhav, McGrady John Ewart
Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK.
Molecules. 2022 Nov 3;27(21):7544. doi: 10.3390/molecules27217544.
MC-SCF wavefunctions for three endohedral Mn/Si clusters, MnSi, MnSi, and [MnSi], show evidence for strong static correlation, both in the Mn-Si bonds ('in-out correlation') and between the two Mn centers ('up-down correlation'). We use both Restricted and Generalized Active Spaces (RAS and GAS) to place constraints on the configurations included in the trial wavefunction, showing that, particularly in the high-symmetry cases, the GAS approach captures more of the static correlation. The important correlating pairs are similar across the series, indicating that the electronic structure of the endohedral Mn unit is, to a first approximation, independent of the size of the silicon cage in which it is embedded.
三个内嵌锰/硅团簇MnSi、MnSi和[MnSi]的多组态自洽场（MC-SCF）波函数表明，在锰-硅键（“内-外关联”）以及两个锰中心之间（“上-下关联”）都存在强静态关联的证据。我们使用受限和广义活性空间（RAS和GAS）来对试探波函数中包含的构型施加约束，结果表明，特别是在高对称情况下，GAS方法能捕捉到更多的静态关联。整个系列中重要的关联对相似，这表明内嵌锰单元的电子结构在一阶近似下与它所嵌入的硅笼大小无关。
