Finite Ligand Size and the Sternheimer Antishielding Factor ?8

Abstract

Two distinct processes, one classical and the other quantum mechanical, have to be considered in allowing for the effect of the finite size of atoms on the shielding of the coupling between crystal and nuclear electric quadrupole moments. The effect of the quantum mechanical process has already been calculated; in this paper we employ a simple numerical technique for evaluating multicentre integrals to calculate the effect of charge penetration. This effect is found to be significant and it suggests that a new approach is necessary in the parameterization of the crystal-nuclear-quadrupole interaction.