Optimum exponent values for 3s, 3p, and 3dorbitals of sulfur in SF6have been calculated in an electrostatic approximation. The sulfur electrons are perturbed by fluorine potentials appropriate to selfhyphen;consistent field wave functions for the fluorine orbitals, and the energy minimized with respect to wavehyphen;function exponents. The optimum values arek3s=2.0,k3p=1.6, andk3d=1.2, corresponding to expansion of 3sand 3porbitals, and contraction of 3d, compared with freehyphen;atom values. The values are remarkably stable to changes in valencehyphen;orbital configurations as between SF6, S+F6minus;, S++F6=, and even Sminus;F6+. They are also little affected by change in hybridization at fluorine, and should therefore be suitable for use in the construction of molecular wave functions.Although the calculated energies include no exchange terms they are still of some interest. They suggest for example that the promotion energy to the configurationsp3d2of sulfur (estimated to be 25ndash;31 eV) can be compensated by the energy of molecule formation.
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