Application of coupled equation method on resonance processes of...

The coupled equation method (CEM) has been applied to investigating the resonance structures for the ground state 1s2 2s 2S of the neutral lithium from the first threshold up to 64.5 eV. Resonance structures of atomic lithium due to single excitations of the 1s and 2s electrons are studied by infinite-order calculations in detail. The effect of spin-orbit splitting is also included for some of the low-lying 1s 2s np resonance, and the influence of the interference between 1s 2s 3S np and 1s 2s 1