Abstract

A number of recent theoretical studies point cut the importance of electron correlation in high lying doubly excited states of atoms¹. In particular, when two electrons are excited into the same shell, it is predicted that a high degree of electron correlation causes some cooperative motion of the electrons and the energy spectrum of these states has a particular structure equivalent to the rotation-vibration spectrum of a linear floppy X-Y-X triatomic molecule². This type of states is often called "Wannier" state³. Some groups of experimentalists have been trying to observe this state of Ba by laser spectroscopic methods³.

© 1988 Optical Society of America