Stein Christopher J, Reiher Markus
ETH Zurich Laboratorium fur Physikalische Chemie Vladimir-Prelog-Weg 2, CH-8093 Zurich.
ETH Zurich Laboratorium fur Physikalische Chemie Vladimir-Prelog-Weg 2, CH-8093 Zurich;, Email:
Chimia (Aarau). 2017 Apr 26;71(4):170-176. doi: 10.2533/chimia.2017.170.
Quantum-chemical multi-configurational methods are required for a proper description of static electron correlation, a phenomenon inherent to the electronic structure of molecules with multiple (near-)degenerate frontier orbitals. Here, we review how a property of these frontier orbitals, namely the entanglement entropy is related to static electron correlation. A subset of orbitals, the so-called active orbital space is an essential ingredient for all multi-configurational methods. We proposed an automated selection of this active orbital space, that would otherwise be a tedious and error prone manual procedure, based on entanglement measures. Here, we extend this scheme to demonstrate its capability for the selection of consistent active spaces for several excited states and along reaction coordinates.
对于具有多个（近）简并前沿轨道的分子的电子结构所固有的静态电子相关现象的恰当描述，需要量子化学多组态方法。在此，我们回顾这些前沿轨道的一个性质，即纠缠熵如何与静态电子相关相关联。轨道的一个子集，即所谓的活性轨道空间，是所有多组态方法的一个基本要素。我们基于纠缠度量提出了一种对该活性轨道空间的自动选择方法，否则这将是一个繁琐且容易出错的手动过程。在此，我们扩展该方案以展示其为几个激发态以及沿着反应坐标选择一致活性空间的能力。
