The superheavy elements we investigate have the following possible ground-state configurations: [Og] 8sk 8pl 7dm 6fw 5gv, where k ≤ 2, l ≤ 6, m ≤ 10, w ≤ 14, v ≤ 18; [Og] stands for the closed-shell Oganesson (Z = 118) configuration. Since it is a priori unclear which electron configuration yields the lowest energy, first we have made some combinatorics and generate the list of all possible placings of nelectrons on the 8sk 8pl 7dm 6fw 5gv valence shells. Then for each configuration, we have performed the Dirac-Fock calculations in the non-relativistic configuration average approximation. For the configurations with the lowest Dirac-Fock energy, the CI-DFS method is utilized to obtain the energy for the particular term. All single and double excitations from the single reference state were included in the configuration space. Since the configuration space drastically increases with the number of the basis set of one-electron wave functions, only the Sturm orbitals with n≤ 10, l≤ 3 were used in the calculations as virtual ones. The Fermi model of the nuclear charge distribution with the root-mean-square nuclear radii as in Ref. [9] was used in the calculations.In Table I we present the results on calculations of the Z = 123 element. The most “suspicious” configurations in being ground state ones are [Og] 8s2 8p17d1 6f1and[Og]8s27d26f1since they have the lowest Dirac-Fock non-relativistic configuration average energy EDFav. The difference between the energies is about 0.1 a.u, with the configuration [Og]8s27d26f1 being lower. If we turn on the interaction between different configurations and perform the CI calculations for all terms we find that [Og] 8s2 8p1 7d1 6f1 configuration’s terms lie lower that all the terms of the [Og]8s2 7d2 6f1configuration.

The present project was dedicated to the determination of the ground state configuration for the superheavy elements with Z > 120. For all possible reasonable configurations of the elements, the CI-DFS method was used to determine the energy of each term within the configuration. Then, the ground state configuration was deduced as the configuration with the lowest energy. All the results are in agreement with the previous works reported in Refs. [5, 6, 7, 9] and in disagreement with the conclusion of the Ref. [8].5.

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Personal Impression

The whole G-RISC program was organized at the highest level. I would like to thank the german principal advisor Dr. G. Plunie who has made my stay in TU Dresden during the program convenient and botherless. Almost every day we had productive discussions on the problem and physics in general.I have made a significant advance in the problem and obtained valuable results.