Top: 4D PSS for energy level E_j = −4.0. The same as in Fig. 9, but here in orange or yellow (the gradient of the colour indicates the ż component) showing a sticky chaotic orbit that acts as an approximate barrier between the orbits that get diffused inwards (green) and those that get diffused outwards (blue). Bottom: Time evolution of FT-LCN for the two sticky chaotic orbits of Fig. 9. A chaotic orbit (blue) diffused faster outwards and reaching very large distances, and a sticky chaotic orbit (green) that behaves like a regular one for very long times and finally converges to a positive LCN.