He-clean Rh(311) scattering has been discussed within the frame of classical and quantum mechanics. These models of TEAS are based on the one particle problem. In the classical case the mass point of the He atom scatters on the He - Rh(311) interaction potential [1] governing by Newton's laws. The scattering has been investigated as a function of impact parameters. Detailed computations show 3D chaotic effects in 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 time dependent Schrödinger equation [2]. The classical and quantum models show the effect of trapping, respectively. Classical model shows chaotic scattering and a non-realistic intensity distribution. The more realistic quantum model provides correct intensity distribution but no any trace of chaotic scattering. The results underline the idea that many published classical chaotic computations do not belong to any real physical system.
 
 

[1] R. Apel, D. Farías, H. Tröger, E. Kristen, K.H. Rieder, Surface Science 364 (1996).

[2] G. Varga, Surface Science, (1999) vol. 441 p. 472-478.