Stabilization Method With The Relativistic Configuration-Interaction Calculation Applied To Two-Electron Resonances

We applied a relativistic configuration-interaction (CI) framework to the stabilization method as an approach for obtaining the autoionization resonance structure of heliumlike ions. In this method, the ion is confined within an impenetrable spherical cavity, the size of which determines the radial space available for electron wave functions and electron-electron interactions. By varying the size of the cavity, one can obtain the autoinization resonance position and width. The applicability of this method is tested on the resonances of He atom while comparing with benchmark data available in the literature. The present method is further applied on the determination of the resonance structure of heliumlike uranium ion, where a relativistic framework is mandatory. In the strong-confinement region, the present method can be useful to simulate the properties of an atom or ion under extreme pressure. An exemplary application of the present method to determine the structure of ions embedded in dense plasma environment is briefly discussed.