Relativistic effects in the photoelectron dynamics of Z$=$118

High-Z atoms are excellent laboratories to study the combination of relativistic and many-electron correlation effects in their electronic structure and dynamics. Radioactive Z$=$118 is very difficult to study experimentally, but. there are theoretical studies [1,2]. In the present work, the relativistic-random-phase approximation (RRPA) [3] at different levels of truncation is employed to explore the final-state correlation effects in the photoelectron dynamics of Z$=$118 to illustrate the relativistic effects resulting from coupling different photoionization channels arising from spin-orbit split subshells, termed the spin-orbit interaction activated interchannel coupling (SOIAIC) effect [4,5]. Coupling of channels arising from spin-orbit split subshells can cause significant changes in the energy dependence of the photoionization parameters in the near-threshold region. Comparison between photoelectron dynamics of Rn on a qualitative level is also carried out in this work, since Z$=$118 is a homologue of Rn with regard to photoionization dynamics. Photoelectron dynamics of 7p, 7s and 6d subshells are investigated and comparison between Z$=$118 and Rn is made. [1] V. Pershina \textit{et al}, J. Chem. Phys. \textbf{129,} 144106 (2008); [2] E. Eliav E \textit{et al}, Phys. Rev. Lett. \textbf{77}, 5350 (1996); [3] W. R. Johnson and C. D. Lin, Phys. Rev. A \textbf{20}, 964 977 (1979); [4] M. Ya. Amusia \textit{et al}, Phys. Rev. Lett. \textbf{88}, 093002 (2002); [5] S. S. Kumar \textit{et al}, Phys. Rev. A \textbf{79}, 043401 (2009).