Chaotic motion in axially symmetric potentials with oblate quadrupole deformation

► We find chaotic motion around a monopole with oblate quadrupole deformation. ► This corrects the statements introduced in [E. Guéron, P.S. Letelier, Phys. Rev. E 63 (2001) 035201]. ► We present an alternative model for the potential due to an oblate deformed nuclei. ► This leads to stochastic regions in the phase space of classical orbits. ► It suggests that the shell structure of single-particle spectrum tends to disappear.