Ab initio calculations of QED radiative corrections to the 2 P 1/2 -2 P 3/2 fine-structure transition energy are performed for selected F-like ions. These calculations are nonperturbative in αZ and include all first-order and many-electron second-order effects in α. When compared to approximate QED computations, a notable discrepancy is found especially for F-like uranium for which the predicted self-energy contributions even differ in sign. Moreover, all deviations between theory and experiment for the 2 P 1/2 -2 P 3/2 fine-structure energies of F-like ions, reported recently by Li et al., Phys. Rev. A 98, 020502(R) (2018), are resolved if their highly accurate, non-QED fine-structure values are combined with the QED corrections ab initially evaluated here. 12.20.Ds,31.15.ac,31,15.am

The magnetic dipole (M1) line strength between the fine-structure levels of the ground configurations in B-, F-, Al-and Cl-like ions are calculated for the four elements argon, iron, molybdenum and tungsten. Systematically enlarged multiconfiguration Dirac-Hartree-Fock (MCDHF) wave functions are employed to account for the interelectronic interaction with the Breit interaction included in first-order perturbation theory. The QED corrections are evaluated to all orders in αZ utilizing an effective potential approach. The calculated line strengths are compared with the results of other theories. The M1 transition rates are reported using accurate energies from the literature. Moreover, the lifetimes in the range of millisecond to picoseconds are predicted including the contributions also from the transition rate due to the E2 transition channel. The discrepancies of the predicted rates from those available from the literature are discussed and a benchmark dataset of theoretical lifetimes is provided to support future experiments.