Effect of screened Coulomb potentials on the resonance states of two-electron highly stripped atoms using the stabilization method

Abstract

Resonance states of C4+, O6+, Ne8+ ions interacting with screened Coulomb potentials have been investigated using the stabilization method. We employ highly correlated exponential basis functions for S-, P-state calculations and employ CI-type basis functions for D-state calculations. We report a total of seven S-wave resonances of which four belong to 2sns (n = 2, 3, 4, 5) series and three belong to the 2pnp (n = 2, 3, 4) series. In addition, a total of eight P-wave resonances of which three belong to 2snp+ (n = 2, 3, 4), three belong to the 2snp− (n = 3, 4, 5) series, two belong to the 2pnd (n = 3, 4) and the lowest D-wave resonance for each systems and each screening parameters below the n = 2 thresholds of the respective subsystems are reported. In the unscreened case, we have found some resonance states that have not been reported before. In the screened case our reported results are new and show some interesting behaviour with and without electron–electron screening.