Stein Christopher J, Pantazis Dimitrios A, Krewald Vera
Department of Chemistry , University of California , Berkeley , California 94720 , United States.
Chemical Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States.
J Phys Chem Lett. 2019 Nov 7;10(21):6762-6770. doi: 10.1021/acs.jpclett.9b02417. Epub 2019 Oct 18.
A new tool for the interpretation of multiconfigurational wave functions representing the spin states of exchange-coupled transition metal complexes is introduced. Based on orbital entanglement measures, herein derived from multiconfigurational density matrix renormalization group calculations, the complexity of the wave function is reduced, thus facilitating a connection with established concepts for the interpretation of magnetically coupled systems. We show that the entanglement of localized orbitals with a small basis set is a good representation of the magnetic coupling topology and that it is sensitive to chemical changes in homologous complexes. Furthermore, we introduce a measure for the magnetic relevance of orbitals in the active subspace and a concept for the quantitative comparison of different chemical species. The approach presented here will be easily applicable to higher nuclearity clusters, providing a direct insight into all states of the Heisenberg spin ladder for systems previously accessible only by single-configurational methods.
本文介绍了一种用于解释表示交换耦合过渡金属配合物自旋态的多组态波函数的新工具。基于从多组态密度矩阵重整化群计算得出的轨道纠缠度量，波函数的复杂性得以降低，从而便于与用于解释磁耦合系统的既定概念建立联系。我们表明，具有小基组的定域轨道的纠缠很好地表示了磁耦合拓扑结构，并且它对同源配合物中的化学变化敏感。此外，我们引入了一种用于活性子空间中轨道的磁相关性的度量以及一种用于不同化学物种定量比较的概念。这里提出的方法将很容易应用于更高核数的簇，为以前只能通过单组态方法研究的系统的海森堡自旋梯子的所有状态提供直接见解。
