摘要
Electron-electron interactions are of fundamental importance for the understanding of structures in bound systems,they are drivers on the de-excitation and relaxation processes of excited atoms.Helium-like ion,as a simplest double-electron system,provides one of the few opportunities to test the two-body relativistic formulation mechanics.It is a very good model to test and study of inter-electron correlations,especially for innermost shell electrons,like 1s,2s,and so on.
