Comparison of 3D classical and quantum mechanical He scattering on Rh(3 1 1)

He-clean Rh(3 1 1) scattering has been discussed within the frame of classical and quantum mechanics. These models of thermal energy atomic scattering on solid surfaces are based on the one particle problem. In the classical case the mass point of the He atom is scattered on the interaction potential of He–Rh(3 1 1) system. The classical equation of motion is solved. The scattering has been investigated as a function of impact parameters. Detailed computations show three-dimensional chaotic effects on trajectories, phase diagrams, deflection angle function and dwell time function. In the case of quantum mechanical model the He atomic beam is described as a Gaussian wave packet. Its time propagation is governed by the time dependent Schrödinger equation. Both the classical and quantum models show trapping effect. The classical model shows chaotic scattering and a non-realistic intensity distribution. The more realistic quantum model provides correct intensity distribution but no trace of chaotic scattering. The results underline the idea that many published classical chaotic computations do not describe any real physical system.