Line Shape for Collisionally Broadened Molecular Transitions: A Quantum Theory Satisfying the Fluctuation Dissipation Theorem

摘要

The dipole autocorrelation function for spectral line broadening is treated in a quantum theory which rigorously satisfies detailed balance on a microscopic level. The approximations involved include the assumption of binary collisions, the neglect of line coupling and the validity of second order perturbation theory. The results are consistent with the impact theory at long times and include the physics of collisions described through an appropriate intermolecular collision potential. Physically realistic trajectories are utilized for the computation of the required matrix elements. The results are shown to be consistent with an analysis of the water vapor continuum. (Author)