Semiclassical calculations with exact trajectory for N2 rovibrational Raman linewidths at temperatures below 300 K

A new model of exact-trajectory semiclassical calculations proposed by Bykov et al. (Atmos Oceanic Opt 1992;5:728) for electrostatic resonance functions is generalized to the case of short-range interactions in the form of atom-atom potential by the help of two-centre expansion. For the first time, explicit expressions are applied to practical calculations of experimentally measured N-2 rovibrational Raman linewidths. Two traditional models of straight-line and parabolic trajectories are also involved in calculations to trace the evolution due to the complication of the trajectory. Thorough comparative analysis is fulfilled for low (113 K) and ordinary (298 K) temperature resonance functions of exact and parabolic trajectory models and significant role of better path description for linewidths (in the range of semiclassical approach validity) is demonstrated. (C) 1999 Elsevier Science Ltd. All rights reserved.