Departament de Química and Institut de Química Computacional i Catàlisi, Universitat de Girona, Maria Aurèlia Capmany 69, 17003 Girona, Spain.
Molecules. 2020 Jan 6;25(1):234. doi: 10.3390/molecules25010234.
The use of centroids of localized orbitals as a method to derive oxidation states (OS) from first-principles is critically analyzed. We explore the performance of the closest-atom distance criterion to assign electrons for a number of challenging systems, including high-valent transition metal compounds, π-adducts, and transition metal (TM) carbenes. Here, we also introduce a mixed approach that combines the position of the centroids with Bader's atomic basins as an alternative criterion for electron assignment. The closest-atom criterion performs reasonably well for the challenging systems, but wrongly considers O-H and N-H bonds as hydrides. The new criterion fixes this problem, but underperforms in the case of TM carbenes. Moreover, the OS assignment in dubious cases exhibit undesirable dependence on the particular choice for orbital localization.
我们批判性地分析了将局域轨道质心用作从第一性原理推导出氧化态 (OS) 的方法。我们研究了最近原子距离准则在为许多具有挑战性的系统分配电子时的性能，包括高价过渡金属化合物、π-加合物和过渡金属 (TM) 卡宾。在这里，我们还引入了一种混合方法，将质心的位置与 Bader 的原子盆地结合起来，作为电子分配的替代准则。最近原子准则对具有挑战性的系统表现相当好，但错误地将 O-H 和 N-H 键视为氢化物。新准则解决了这个问题，但在 TM 卡宾的情况下表现不佳。此外，在可疑情况下的 OS 分配表现出对轨道定域特定选择的不良依赖性。
