**Ephraim Eliav (Tel Aviv University) | **Benchmark electronic structure calculations at the edge of the Periodic Table |

High-accuracy calculations of atomic properties of the heaviest elements are reviewed (for more details see [1]). The properties discussed include electronic structure and energetics (ionization potentials, electron affinities, excitation energies), which are associated with the spectroscopic and chemical behavior of these elements and are therefore of considerable interest. Accurate predictions of these quantities require high order inclusion of relativity, QED and electron correlation effects, as well as large, converged basis sets. The Dirac-Coulomb-Breit Hamiltonian, which includes all terms up to second order in the fine-structure constant, serves as the framework for the treatment; higher-order Lamb shift terms are considered in most cases. Electron correlation is treated by the Fock-space coupled cluster method, enhanced by the intermediate Hamiltonian scheme, allowing the use of large, converged model (P) spaces.

The calculations on superheavy elements (SHE) are supported by the very good agreement with experiment obtained for the lighter homologues, usually within a few hundredths of an eV, and similar accuracy is expected for the SHEs, with Z>100, for which experimental values are scarce. Many of the properties predicted for these species differ significantly from what may be expected by straightforward extrapolation of lighter homologs, demonstrating that the structure and chemistry of SHEs are strongly affected by relativity and electron correlation.

The major scientific challenge of the calculations is to find the electronic structure and basic atomic properties of a SHE and assign its proper place in the Periodic Table. The extended Periodic Table up to E174 is presented on the base of our benchmark calculations. Different unusual inclinations and irregularities of the Periodic Law at the edge of extended Periodic System are discussed.

References:

1) E. Eliav, A.Borschevsky, U.Kaldor, in “Handbook of Relativistic Quantum Chemistry”, Ed. W. Liu 2015, Springer-Verlag Berlin Heidelberg, chapter 26

When: June 14, 2023 2:00 PM (Israel Standard Time).

__Where:__ Room 223, Multipurpose Bldg. & over Zoom