POLARIZATION PROPAGATOR ANALYSIS OF THE THROUGH-SPACE TRANSMISSION OFSPIN-SPIN COUPLING-CONSTANTS BY OVERLAP OF LONE PAIRS

The inner projections of the polarization propagator (IPPP) technique together with the decomposition into contributions from localized orbi tals within the polarization propagator approach (CLOPPA) are applied to study different features of the spin-spin coupling constants betwee n atoms bearing lone pairs which overlap to a considerable extent. Mod el compounds are chosen to study 4J(FN), 2J(FN), J2(FN), 2J(PP) and 2J (SeSe) couplings. Calculations are performed at the INDO level. Total calculated couplings are in reasonable agreement with experimental val ues. Through space transmitted components as well as total couplings a re analyzed yielding insight into factors affecting both the polarizat ion propagator and the perturbations. It is found that only the F and Se lone pairs with the largest s character make significant contributi ons to the through space transmission of the Fermi contact interaction .