Lampert Julianne S, Krogmeier Timothy J, Schlimgen Anthony W, Head-Marsden Kade
Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 61630, USA.
Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA.
J Chem Phys. 2024 Nov 7;161(17). doi: 10.1063/5.0232316.
Accurate modeling of transition metal-containing compounds is of great interest due to their wide-ranging and significant applications. These systems present several challenges from an electronic structure perspective, including significant multi-reference characters and many chemically relevant orbitals. A further complication arises from the so-called double d-shell effect, which is known to cause a myriad of issues in the treatment of first-row transition metals with both single- and multi-reference methods. While this effect has been well documented for several decades, a comprehensive understanding of its consequences and underlying causes is still evolving. Here, we characterize the second d-shell effect by analyzing the information entropy of correlated wavefunctions in a periodic series of 3d and 4d transition metal molecular hydrides and oxides. These quantum information techniques provide unique insight into the nuanced electronic structure of these species and are powerful tools for the study of weak and strong correlations in the transition metal d manifold.
由于含过渡金属化合物具有广泛且重要的应用，因此对其进行精确建模备受关注。从电子结构角度来看，这些体系存在若干挑战，包括显著的多参考特征以及许多与化学相关的轨道。所谓的双d壳层效应引发了进一步的复杂性，已知该效应在使用单参考和多参考方法处理第一行过渡金属时会导致大量问题。尽管这种效应在几十年前就已有详尽记录，但对其后果及根本原因的全面理解仍在不断发展。在此，我们通过分析一系列3d和4d过渡金属分子氢化物及氧化物中相关波函数的信息熵来表征第二d壳层效应。这些量子信息技术为深入了解这些物质细微的电子结构提供了独特视角，并且是研究过渡金属d轨道中弱关联和强关联的有力工具。
