SCF-X_α Scattered Wave Studies on Bonding and Ionization Potentials. I. Hexafluorides of Group VI Elements

A SCF-X_α-SW calculation has been carried out for the hexafluorides of the group VI elements S, Se, and Te. The bonding of these molecules is compared by using the charge distribution in different spatial regions in these molecules. The central atom-ligand bond is found to increase in polarity as one moves from S to Te. In contrast to simple overlap arguments, the e_g level is always higher in energy than the t_2g level. The calculated ionization spectra agree well with the experimental measurements. Finally, the d orbital participation has been studied for SF₆. The inclusion of d components is necessary in order to reproduce the experimental level ordering. However, its effect on the charge distribution (and possibly also on the bonding) is minor.