Critical Stability of a Model Two‐Electron System With Tunable Interelectronic Repulsion

ABSTRACT The stability of a model two‐electron system with tunable interelectronic repulsion has been explored with respect to a scaling parameter . The complex scaling method within an orbital‐based configuration expansion and the Ritz variational method with an explicitly correlated Hylleraas‐type basis set are considered for this purpose. An estimation of critical scaling parameter , at which the bound state transforms into a shape resonance state, is reported. The position and width of the quasibound state for are calculated by adopting the complex scaling method. The onset of quantum phase transition in the vicinity of is discussed through the estimation of geometrical properties such as radial moments.