Abstract
We investigate the stability of two-electron ions interacting with Yukawa potentials with varying using correlated exponential wave functions based on the Ritz variational method. The critical screening parameter as a function of the nuclear charge , the critical nuclear charge as a function of the screening parameter , and the ionization energies in terms of the screening parameter and are reported. The critical charge for the bare Coulomb system (, , ) obtained using 700-term correlated exponential wave functions is in reasonable agreement with the reported results in the literature. The critical screening parameter, critical nuclear charge, and ionization energy for the Yukawa system (, , ) exhibit interesting behaviors. The possible existence of Borromean states and quasibound resonant states is also discussed.
- Received 3 January 2019
DOI:https://doi.org/10.1103/PhysRevA.99.042514
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