Bound and resonance states of highly charged H‐ and He‐like ions under weakly coupled plasma environment

Abstract The position of bound () states as well as doubly excited resonance , () states of symmetry has been determined for highly charged He‐like ions (, , , , , and Ar 16+ ) along with their respective one‐electron thresholds (, , and ) under weakly coupled plasma environment. These particular ions and their respective charge states are selected due to their frequent occurrence in astrophysical and laboratory plasmas. Ritz variational method with multi‐exponent explicitly correlated Hylleraas type basis and pure‐exponential basis set are adopted for tackling He‐ and H‐like ions, respectively. The resonance width of a few low‐lying resonance states is determined using the stabilization method under different plasma conditions. Ionization potential depression is noted for both the bound and resonance states of the plasma‐embedded ions. It is evident that the width (or the lifetime) of the considered resonance states originating from different dominant configurations follows different patterns w.r.t. the plasma screening length.