Magnetically induced current density from numerical curls of nucleus independent chemical shifts

Abstract

Instead of computing magnetically induced current densities (MICD) via the wave function and their quantum mechanical definition, one can also use the differential form of the Ampère–Maxwell law to obtain them from curls via spatial derivatives of the induced magnetic field. In magnetic molecular response calculations, the latter can be done by taking the numerical derivative of the so-called “nucleus-independent chemical shifts” (NICS), which are implemented in many standard quantum chemical programs. The resulting numerical MICD data is in contrast to any other first-principles based numerically obtained MICDs computed via the wave function route, virtually divergence-free.