  We identify the dominant collisional decoherence mechanism which serves to
stabilize and super-select the configuration states of chiral molecules. A
high-energy description of this effect is compared to the results of the exact
molecular scattering problem, obtained by solving the coupled-channel
equations. It allows to predict the experimental conditions for observing the
collisional suppression of the tunneling dynamics between the left-handed and
the right-handed configuration of D2S2 molecules.
