Electronic structure of heavy-element oxides and fluorides: XANES L_(III) spectroscopy and DFT calculations

摘要

XANES L_(III) spectra of series Tl, Pb and Bi compounds are studied. The data of DFT-ZORA calculations are in satisfactory agreement with the results of XANES spectroscopy of heavy-element fluorides and oxides. The fine structure of L_(III) absorption near edge for Tl~(3+) , Pb~(4+) and Bi~(5+) ions is associated with transitions to the atomic 6s_(1/2), 6p_(1/2) (relativistic allowed) and 6d-7s terms. The "superfluous" lines observed in XANES spectra of Tl~+, Pb~(2+) and Bi~(3+) oxides and fluorides are associated with the mix of 6s_(1/2) and 6p_(3/2) states of heavy 6s~2 ions.