Summa Francesco Ferdinando, Monaco Guglielmo, Zanasi Riccardo, Lazzeretti Paolo
Dipartimento di Chimica e Biologia "A. Zambelli," Università degli studi di Salerno, via Giovanni Paolo II 132, Fisciano, Salerno 84084, Italy.
J Chem Phys. 2022 Apr 21;156(15):154105. doi: 10.1063/5.0089605.
The electronic current density, induced in a molecule by the optical magnetic field associated with a frequency-dependent monochromatic plane wave, assumed to be spatially uniform within the electric quadrupole approximation, has been studied by using a theoretical method based on a continuous translation of its origin. The induced electronic current density vector field designated by this procedure, invariant of the origin for any point of the molecular domain, is obtained via a computational scheme, formally annihilating the diamagnetic contribution of the conventional common-origin approach based on perturbation theory. In a preliminary application of the theoretical methods outlined in the present work, the simple molecule of lithium hydride has been investigated. Particular attention has been paid to the structure of induced electronic current density for several values of the magnetic field frequency by investigating equilibrium points of four different types, organized in stagnation lines, which constitute its stagnation graph, i.e., a topological fingerprint of the vector field conveying complete information in the condensed form, to verify the fulfillment of fundamental requirements, e.g., the continuity equation and the Poincaré-Hopf theorem on spherical and toroidal surfaces.
在电四极近似下，假设与频率相关的单色平面波相关的光磁场在空间上是均匀的，通过使用一种基于其原点连续平移的理论方法，研究了在分子中感应出的电子电流密度。通过该程序指定的感应电子电流密度矢量场，对于分子域的任何点都是原点不变的，它是通过一种计算方案获得的，该方案形式上消除了基于微扰理论的传统共原点方法的抗磁贡献。在本工作中概述的理论方法的初步应用中，对氢化锂这个简单分子进行了研究。通过研究组织在停滞线中的四种不同类型的平衡点，特别关注了几种磁场频率值下感应电子电流密度的结构，这些平衡点构成了它的停滞图，即矢量场的拓扑指纹，以浓缩形式传达完整信息，从而验证基本要求的满足情况，例如连续性方程以及球面和环面上的庞加莱 - 霍普夫定理。
