These measurements represent a unique determination of an atomic rank-6 multipole (hexacontatetrapole). We have demonstrated that the hexacontatetrapole plays an important part in the shape of the excited charge cloud. (see figure at right and graph above.)

Our next set of experiments will inolve excited states of KrI and ArII. The states of krypton are interesting since they are intermediately coupled (L or S or neither are good quantum numbers), which are responsible for rectangular "density matrices." We are also planning to extend the ArII work to cover the 3p4(3P)4p configuration of ArII, which will allow us to study the distribution of orbital and spin angular momentum between the outer electron and the core.