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

• Excitation energies and lifetimes for the lowest 301 levels of Nb XXX are presented. • The atomic data for E1, M1, E2, and M2 transitions in Nb XXX are presented. • The calculations are performed using the fully relativistic multiconfiguration Dirac-Hartree-Fock (MCDHF) method. • Comparisons with available experimental and other theoretical results are performed. • The accuracy of E1, M1, E2, and M2 line strengths of Nb XXX is estimated. 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 3 snl (n = 3 − 6, l = 0 − 5), 3 pnl (n = 3 − 5, l = 0 − 4), and 3 dnl (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. [ABSTRACT FROM AUTHOR]