CARBON CLUSTER ION DRIFT MOBILITIES - THE IMPORTANCE OF GEOMETRY AND VIBRATIONAL EFFECTS

Research groups have identified the structures of carbon cluster ions by matching drift mobilities of these species observed in ion chromato graphy experiments to calculated mobilities of proposed structures. We examine the validity of two central approximations used to calculate mobilities of these carbon cluster ions through inert gases. The appro ximations are that calculated mobilities are not strongly dependent on the quality of the optimized cluster geometry used to calculate the m obilities, and that the amount of internal energy present in the clust ers under experimental conditions does not significantly distort them from their equilibrium geometries. The theoretical results reported he re are consistent with the experimental assumptions.