“…Above dimension three, only sporadic families of second-order superintegrable systems are known, such as the harmonic oscillator, a generalisation of the Kepler system [PP90,BH09], respectively the hydrogen atom [Nie79], the Smorodinsky-Winternitz system I [FMS + 65], also referred to as the generic system, and the Smorodinsky-Winternitz system II [KKMP07], which can be interpreted as an anisotropic oscillator model [RTW08]. 1 From these, further n-dimensional families can be obtained through Bôcher contractions [Bôc94,KKMP07] or coupling constant metamorphosis (aka Stäckel transforms) [Pos10].…”