Quantum-number–dependent energy level shifts of ions in dense plasmas: A generalized analytical approach

Dense plasma effects on bound energy levels have been studied with relativistic atomic structure simulations that include intermediate coupling and configuration interaction. A general analytical formula is proposed that predicts the energy of LSJ-split levels for wide conditions of density and finite temperature and any atomic element. The achieved precision of the analytical approach allowed even to describe energy level crossings and the breakdown of level degeneration induced by dense plasma effects. Finally, a further simplification of the proposed method is developed that requests only information on energy level energies and quantum numbers of isolated atoms that are readily available.