Extended analysis of the system of even configurations of Ta II

We performed a parametric study of the fine (fs) and hyperfine structure (hfs) for the even parity configurations of ionized tantalum (Ta II) using improved experimental fs and hfs data for 88 levels. A multi-configuration fitting procedure was performed for 47 configurations taking into account second-order perturbation theory including the effects of closed to open shell excitations. The fs and hfs parameters were calculated. Predicted values of level energies up to 86000cm−1 are given, as well as gJ-Landé factors, magnetic dipole and electric quadrupole hyperfine structure constants A and B, when no experimental values are available.