Relativistic calculation of the electronic structure of UF6

Using a one-component relativistic theory we have obtained the self-consistent (SCF) one-electron levels of UF6 via the multiple scattering (MS) Xα method. The calculated ionization energies are found to be in good agreement with the photoionization spectrum. Our first electronic transition (dipole forbidden) energy at 3.34 eV agrees well with the onset of absorption and the experimentally assigned transition at 3.04 eV. An analysis of the spin--orbit parameters, calculated via perturbation theory, is given. It is found that the contributions from the 6p components are especially important. We conclude that the absorption spectrum can not be interpreted in terms of the spin--orbit splitting of the highest occupied MO (t/sub l/u). A comparison is made with other relativistic (and nonrelativistic) one-electron calculations of UF6. This comparison yields reasonable agreement on the relativistic one-electron structure of this molecule