Ionization Potentials, Electron Affinities, Resonance Excitation Energies, Oscillator Strengths, And Ionic Radii of Element Uus (Z = 117) and Astatine

Abstract

Multiconfiguration Dirac-Fock (MCDF) method was employed to calculate the first five ionization potentials, electron affinities, resonance excitation energies, oscillator strengths, and radii for the element Uus and its homologue At. Main valence correlation effects were taken into account. The Breit interaction and QED effects were also estimated. The uncertainties of calculated IPs, EAs, and IR for Uus and At were reduced through an extrapolation procedure. The good consistency with available experimental and other theoretical values demonstrates the validity of the present results. These theoretical data therefore can be used to predict some unknown physicochemical properties of element Uus, Astatine, and their compounds.

Ionization potentials and electron affinities of the superheavy elements 115–117 and their sixth-row homologues Bi, Po, and At

“…The best agreement for Bi and element 115 is obtained with the 4c-FSCC results of Eliav et al [17]; the method used there is rather similar to the present scheme, but the basis sets were smaller. The results of Chang et al [7] for At and element 117 include empirical corrections obtained by fitting calculated values for the lighter homologues Cl-I to experiment, and are close to the ab initio values presented here. The 4c-DFT predictions [9][10][11] show good agreement with our values for element 117, but differ by 0.1-0.4 eV for other elements.…”

“…The empirically corrected MCDF results of Ref. [7] for At and element 117 PHYSICAL REVIEW A 91, 020501 (R) (2015) are in good agreement with present numbers, higher by just 0.17 eV. Finally, 4c-DFT performed well for element 117 [11], but differed by 0.4 eV from present results for element 115 [9], Table III shows the calculated electron affinities.…”

“…Note that the "experimental" EAs of Po and At quoted in [20] from the compilation of Hotop and Lineberger [29] are, in fact, the 1969 semiempirical estimates of Zollweg [28], The MBPT [14] and the CASPT2 [15] results for the 6p elements are lower than the present values by 0.2-0.3 eV. The MCDF results with empirical corrections [7] are close to the CCSD(T) values for At and 117; the recent MCDF study of Li et al [8] is of better quality, with results close to ours for Po and At without using corrections. The FSCC results for Bi and element 115 [17] are close to the present values; larger disagreement is seen for element 117 [19], due to the limited basis set used.…”

Electronic structure theory of the superheavy elements

“…The IP of At was measured by resonance ionization laser ion source (RILIS) studies, giving the experimental value IP = 9.317510(8) eV, compared with the MCSCF value of 9.24(15) eV and the CC result of 9.315(12) eV [145]. An earlier MCSCF calculation, with corrections derived from extrapolating errors of results for lighter halogens [146], gave 9.35(1) eV. This is rather close, but the error bounds are too optimistic.…”

The ISOLDE facility and the HIE-HISOLDE project: Recent highlights

“…Further new ab-initio calculations were done using multi-configuration Dirac-Fock and Dirac-Coulomb coupled cluster calculations. The former provides a conceptually simple approach for computing excitation energies and IP of heavy elements, but core-valence and core-core correlations are not taken into account [5]. In the latter the Dirac08 program package was used [6], correlation up to the last 38 electrons were taken into account giving an IP of 9.307 eV.…”