Electron–electron interaction energy in He-like isoelectronic sequence with Z = 2–133

Abstract

Via a differential comparison of the binding energies between H- and He-like ions, the electron–electron interaction energies of the states and () in the He-like isoelectronic sequence are obtained over a wide range of the nuclear charge by using fully relativistic multiconfiguration Dirac–Hartree–Fock and configuration interaction methods. Contributions from the Coulomb and Breit interactions, the nuclear effects, the self-energy and vacuum polarization corrections are evaluated. The results show that, the one-electron corrections to the electron–electron interaction are nearly cancelled out during the deduction of the interelectron interaction energies. Besides the Coulomb interaction, the Breit interaction plays a significant role in the electron–electron interaction for high- ions; it contributes 23% of the electron–electron interaction energy at