The Oriented and Flux-Weighted Current Density Stagnation Graph of LiH

Abstract

A scheme is introduced to quantitatively analyze the magnetically induced molecular current density vector field J. After determining the set of zero points of J, which is called its stagnation graph (SG), the line integrals -1/mu_0 \int_li B.dl along all edges of the connected subset of the SG are determined. The edges are oriented such that all line integrals are non-negative and they are weighted with the resultants. An oriented flux-weighted (current density) stagnation graph (OFW-SG) is obtained. Since J is in the exact theoretical limit divergence free and due to the topological characteristics of such vector fields the flux of all separate vortices and neighbouring vortex combinations can be determined by adding the weights of cyclic subsets of edges of the OFW-SG. The procedure is exemplified by the case of LiH for a perpendicular and weak homogeneous external magnetic field B.