Calculations of the spectra of superheavy elementsZ=119andZ=120+

Abstract

High-precision calculations of the energy levels of the superheavy elements $Z=119$ and $Z={120}^{+}$ are presented. Dominating correlation corrections beyond the relativistic Hartree-Fock method are included to all orders in the Coulomb interaction using the Feynman diagram technique and the correlation potential method. The Breit interaction and quantum electrodynamics radiative corrections are considered. Also, the volume isotope shift is determined. A similar treatment for Cs, Fr, ${\mathrm{Ba}}^{+}$, and ${\mathrm{Ra}}^{+}$ is used to gauge the accuracy of the calculations and to refine the ab initio results.