We are studying what atoms and ions look like after being excited by electron impact. The pictures shown here represent the individual multipole moments of the Ar⁺ (3p⁴ 4p ²F) state resulting from the ionization of neutral ground-state argon by ~40 eV electrons. The atom actually looks like the "composite F state" picture. Until these experiments, no one had ever measured an atomic hexacontatetrapole (64-pole) moment. This work is discussed in a paper published in Physical Review Letters (H.M. Al-Khateeb, B.G. Birdsey, and T.J. Gay, 85, 4040 (2000)). (See it here). You can also find a discussion of multipoles here.

Check out these other moments:

• Hexacontatetrapole
• Composite F State
• Hexadecapole
• Quadrupole