Abstract
In the frame of binary collisions, it is shown that in addition to the well known unbounded trajectories, the bounded trajectories may contribute significantly to the calculation of time correlation functions. The relative influences of the different contributions is strongly temperature dependent. An illustration is made in the case of the radial distribution function g (r). Moreover, it is shown that under specific conditions, the unbounded contribution must be taken into account in the study of the temperature dependence of linewidths.