Study of correlations with ions (theory)

This paper surveys our current knowledge of the nature of angular and radial correlations between electrons in doubly-excited states of atoms, with special emphasis on the ions H- and N5+. Strong correlations are observed in these systems, particularly at high excitation. The states fall into two classes depending on the type of radial correlations in them. Negative and positive ions display many common features but also differ in important respects in one class of states. © 1991