Atomic structure calculations of super heavy noble element oganesson (Z=118)

We calculate the spectrum and allowed E1 transitions of the superheavy element Og (Z=118). A combination of configuration interaction (CI) and perturbation theory (PT) is used (Dzuba $\mathit{\text{et}}\mathit{\text{at.}}$ Phys. Rev. A, $\mathbf{\text{95}}$, 012503 (2017)). The spectrum of lighter analog Rn I is also calculated and compared to experiment with good agreement.