Analysis of the projection of the total orbital angular momentum along the interelectronic axis for doubly excited states of atoms

Abstract

Doubly excited states of two-electron atoms and ions are calculated using the configuration interaction method and the resulting wavefunctions are analysed in the body frame of the atom. The authors have computed the percentage of the projection (T) of the total orbital angular momentum L along the interelectronic axis for the 3l3l' and 3l4l' doubly excited states. It is shown that along each rotor series, the projection is dominated by a single T component for small L states and that these states are well described by the molecular model. For the high-L states along the rotor series, admixture of different T components is large and these states display properties characteristic of a shell model. The relation between the purity of T projection and the T doubling is also discussed.