POLARIZATION PROPAGATOR ANALYSIS OF SPIN-SPIN COUPLING-CONSTANTS

The analysis of electronic mechanisms that define indirect NMR spin-sp in coupling constants can be efficiently carried out by combining the polarization propagator formalism with the use of localized molecular orbitals. This approach is applied to study several trends of one-bond couplings along the Periodic Table when one of the coupled nuclei bea rs a lone pair. This analysis is preceded by a revision of the fundame ntals of the method in which its approximations, shortcomings and capa bilities are commented on. A brief overview of results already publish ed in the literature is also given. The relationship between the class ical approach of Pople and Santry and the polarization propagator calc ulation of the Fermi contact term is discussed.