Exact treatment of classical trajectories governed by an isotropic potential for linewidth computations

• Published in: Molecular physics Vol. 102; no. 16-17; pp. 1759 - 1765
• Main Authors: Afzelius, M., Buldyreva, J., Bonamy, J.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 20.08.2004
• Subjects: Atom and Molecular Physics and Optics; Atom- och molekylfysik och optik; Fysik; Natural Sciences; Naturvetenskap; Physical Sciences
• ISSN: 0026-8976; 1362-3028; 1362-3028
• DOI: 10.1080/00268970412331287098

Two models for exact classical trajectories in the field of an isotropic potential are investigated for the purpose of semiclassical linebroadening calculations. The first directly uses the exact solution of the classical equation of motion. The second starts from the equation of motion and computes the trajectory by numerical solution of the differential equations. In the framework of both models, all the computations are performed numerically, thus allowing the use of refined ab initio potential energy surfaces. For the example of the linebroadening of pure nitrogen and carbon monoxide, it is shown that, owing to the dominant short-range forces in these self-perturbed molecular systems, the limiting case corresponding to traditional parabolic trajectories can be used without any important loss of precision.