Magnetically Induced Current Density from Numerical Positional Derivatives of Nucleus Independent Chemical Shifts

TL;DR

This paper introduces a method to compute magnetically induced current densities using numerical derivatives of nucleus-independent chemical shifts, offering a divergence-free alternative to wave function-based calculations.

Contribution

It presents a novel approach to calculate induced current densities from NICS derivatives, simplifying computations and improving numerical stability.

Findings

Numerical MICD data is divergence-free.

Method provides an alternative to wave function-based MICD calculations.

Applicable with standard quantum chemical programs.

Abstract

Instead of computing magneticallly induced (MI) current densities (CD) via the wave function and their quatum mechanical definition one can also use the differential form of the Amp\`ere-Maxwell law to obtain them from spatial derivatives of the induced magnetic field. In magnetic molecular response calculations, the latter can be done by numerical derivativation of the so called ``nucleus-independent chemical shifts'' (NICS) which are avaialable to many standard quantum chemical programs. The resulting numerical MICD data is in contrast to other numerically obtained MICDs computed via the wave function route, virtually divergence-free.