Pseudo-Relativistic Hartree-Fock and Fully Relativistic Dirac-Hartree-Fock Calculations of Radiative Parameters in the Fifth Spectrum of Lutetium (Lu V)

Using two independent theoretical methods based on the pseudo-relativistic Hartree-Fock (HFR) and the fully relativistic Multiconfigurational Dirac-Hartree-Fock (MCDHF) approaches, we computed the radiative parameters (transition probabilities and oscillator strengths) corresponding to the spectrum of quadruply ionized lutetium (Lu V). The agreement observed between both sets of results allowed us to deduce the radiative rates for a large amount of transitions in order to calculate the contribution of this ion to the opacity of kilonovae in their early phases, i.e., for T = 25,000 K. The results obtained were compared to previous data computed for other quadruply ionized lanthanide atoms, namely La V, Ce V, Pr V, Nd V and Pm V, in order to highlight the main contributors to the opacity among these ions under kilonovae conditions where the V-th spectra are predominant.