Berger Raphael J F, Dimitrova Maria
Fachbereich für Chemie und Physik der Materialien, Paris-Lodron Universität Salzburg, Jakob-Harringerstr. 2a, A-5020 Salzburg, Österreich, Austria.
Department of Chemistry, Faculty of Science, University of Helsinki, P.O. Box 55, A. I. Virtasen aukio 1, FI-00014, Finland.
Phys Chem Chem Phys. 2022 Oct 5;24(38):23089-23095. doi: 10.1039/d2cp02262a.
A new natural scheme is introduced to analyze quantitatively the magnetically induced molecular current density vector field, . The set of zero points of , which is called its (SG), has been previously used to study the topological features of the current density of various molecules. Here, the line integrals of the induced magnetic field along edges of the connected subset of the SG are calculated. The edges are oriented such that all weights, , flux values become non-negative, thereby, an oriented flux-weighted (current density) stagnation graph (OFW-SG) is obtained. Since in the exact theoretical limit, is divergence-free and due to the topological characteristics of such vector fields, the flux of all separate vortices (current density domains) and neighbouring connected vortices can be determined exactly by adding the weights of cyclic subsets of edges (, closed loops) of the OFW-SG. The procedure is exemplified by the minimal example of LiH for a weak homogeneous external magnetic field, , perpendicular to the chemical bond. The OFW-SG exhibits one closed loop (formally decomposed into two edges), and an open line extending to infinity on both of its ends. The method provides the means of accurately determining the strength of the current density even in molecules with a complicated set of distinct vortices.
引入了一种新的自然方案来定量分析磁感应分子电流密度矢量场。其零点集被称为奇异图（SG），此前已被用于研究各种分子电流密度的拓扑特征。在此，计算了沿奇异图连通子集边缘的感应磁场的线积分。对边缘进行定向，使得所有权重、通量值均为非负，从而得到一个定向通量加权（电流密度）停滞图（OFW - SG）。由于在精确的理论极限下，无散度，并且由于此类矢量场的拓扑特性，通过将OFW - SG的边的循环子集（，闭环）的权重相加，可以精确确定所有单独涡旋（电流密度域）和相邻连通涡旋的通量。以垂直于化学键的弱均匀外磁场下的LiH最小示例对该过程进行了举例说明。OFW - SG呈现出一个闭环（形式上分解为两条边）以及一条两端延伸至无穷远的开放线。该方法提供了即使在具有复杂的不同涡旋集的分子中也能精确确定电流密度强度的手段。
