Chaos in Axially Symmetric Potentials with Octupole Deformation
  Classical and quantum mechanical results are reported for the single particle motion in a harmonic oscillator potential which is characterized by a quadrupole deformation and an additional octupole deformation. The chaotic character of the motion is srongly dependent on the quadrupole deformation in that for a prolate deformation virtually no chaos is discernible while for the oblate case the motion shows strong chaos when the octupole term is turned on. 
W.Dieter Heiss, Rashid G. Nazmitdinov and Stefanel Radu