Benchmark Calculations of Atomic Properties of the Superheavy Elements
Dr. Anastasia Borschevsky (GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt)

Chemical studies on superheavy elements are among the most fundamental fields of research [1]. They seek to probe the lower part of the periodic table, where nuclei become unstable and the relativistic effects on the electronic shells are extremely strong. Due to the short lifetimes and the low production rates of the superheavy atoms, their chemical investigations are extremely challenging, and theoretical predictions may be of assistance both in designing the experiment and in the interpretation of its results. In order to be reliable, atomic calculations performed on the superheavy elements must treat relativity and electron correlations explicitly.
We have performed benchmark calculations of ionization potentials, electron affinities, and static dipole polarizabilities of the 7p and 8s elements (Z=112 to Z=120) [2]. These properties were calculated within the framework of the fully relativistic 4-component Dirac-Coulomb-Breit Hamiltonian, with the electron correlation treated using the Fock space coupled cluster approach (FSCC) [3], augmented by the intermediate Hamiltonian method [4]. This combination of methods makes an extremely powerful computational tool, allowing us to achieve meV precision. In order to assess the accuracy of our results, similar calculations were carried out for the lighter homologues, elements Tl to Ra, giving excellent agreement with experimental values where available. We expect the same high accuracy for our predictions for the superheavy elements.
In the seminar, I will introduce the methods that we employ for treatment of relativity and electron correlation, present the results of our calculations, focusing on elements 119 and 120, and discuss the trends in the groups, demonstrating the dramatic influence of relativistic effects on atomic properties of the superheavy elements.

[1] The Chemistry of Superheavy Elements, M. Schädel, Ed; Kluwer: Dordrecht, The Netherlands (2003)

[2] V. Pershina, A. Borschevsky, E. Eliav, and U. Kaldor, in J. Chem. Phys 128, 024707 (2008); J. Chem. Phys 129, 144106 (2008); J. Phys. Chem. 112, 13712 (2008); Chem. Phys. Lett. 132, 49 (2009)

[3] E. Eliav, U. Kaldor, and Y. Ishikawa, Phys. Rev. A 49, 1724 (1994)

[4] A. Landau, E. Eliav, and U. Kaldor: Chem. Phys. Lett. 313, 399 (1999); J. Chem. Phys 115, 2389 (2001); J. Chem. Phys 122, 224113 (2005)