Radial and angular correlations and the classification of intershell 2l2l^′3l^″ triply excited states of atoms

We analyzed radial and angular correlations of 50 2l2l^′3l^″ triply excited states of atoms. Using hyperspherical coordinates, we examined channel wave functions in the body-fixed frame to identify elementary normal modes of the correlated motion of the three electrons. For these states, we showed that the bending vibrational modes characterizing the angular correlations are the same as those in 2l2l^′2l^″ and 3l3l^′3l^″ intrashell states, but additional “+” or “-” quantum numbers are needed to distinguish the symmetric or antisymmetric stretch of the outer electron with respect to the two inner ones for the 2l2l^′3l^″ intershell states.