Multiple scales and nonadiabatic effects in molecular quantum dynamics

The full quantum dynamical (QD) description of molecules includes multiple scales in particular if particles of essentially different masses are included. This makes full QD simulations of larger molecules simply impossible. In real life molecular dynamics one deals with this problem by introducing simplified "mixed quantum-classical" models which describe the heavy particles of the molecule by the means of classical mechanics and only a small portion by the means of a wavefunction.

This talk will present two of these simplified models. By using the techniques of the previous talk "Weak Convergence Methods and Adiabatic Results in Classical and Quantum Mechanics", it will be discussed under which circumstances these models gain a suitable approximation of the true QD solution. The discussion will be concentrated on the understanding of the nonadiabatic effects which may cause such simplified descriptions to fail and on the alternatives which may prevent such failure.