Fully relativistic energies, transition properties, and lifetimes of lithium-like germanium

Abstract

Employing two fully relativistic methods, the Multi-reference Configuration Dirac-Hartree-Fock (MCDHF) method and the Relativistic Many-Body Perturbation Theory (RMBPT) method, we report energies and lifetime values for the lowest 35 energy levels of the (1s$^2)nl$ configurations (where the principal quantum number $n$ = 2-6 and the angular quantum number $l$ = 0,...,$n$-1) of lithium-like Germanium (Ge XXX), as well as complete data on the transition wavelengths, radiative rates, absorption oscillator strengths, and line strengths between the levels. Both the allowed (E1) and forbidden (magnetic dipole M1, magnetic quadrupole M2, and electric quadrupole E2) ones are reported. The results from the two methods are consistent with each other and align well with previous accurate experimental and theoretical findings. We assess the overall accuracies of present RMBPT results to be likely the most precise ones to date. The present fully relativistic results should be helpful for soft X-ray laser research, spectral line identification, plasma modeling and diagnosing.