Wavelengths and E1, E2, M1, and M2 line strengths in Nb XXX

The calculations are performed to calculate the excitation energies, wavelengths, line strengths, transition probabilities, and weighted oscillator strengths for the electric-dipole (E1), electric-quadrupole (E2), magnetic dipole (M1), and magnetic-quadrupole (M2) transitions between the lowest 301 fine-structure levels of the 3snl (n = 3 6, l = 0 5), 3pnl (n = 3 5, l = 0 4), and 3dnl (n = 3 5, l = 0 4) configurations in Mg-like niobium, Nb XXX. In addition, the level designations in the LS- and jj-coupling schemes and lifetimes are presented. The calculations are carried out using the GRASP2018 atomic structure package which is based on the multiconfiguration Dirac-Hartree-Fock (MCDHF) method, with the contributions of the Breit interaction and quantum electrodynamics (QED) corrections included. The accuracy of the present energies, lifetimes, and transition data is calculated utilizing a comparison of the results from the present MCDHF largest layers from two different approaches, as well as the comparison with theoretical and experimental data that are currently accessible.