2023 Articles

The j and k dependencies of the line coupling and line mixing effects: Theoretical studies of the relaxation matrices of N₂-broadened CH₃D

Ma, Qiancheng; Boulet, C.

Line coupling and line mixing effects in parallel and perpendicular bands of CH₃D perturbed by N₂ have been studied. The work focuses on exhibiting the j and k dependencies of these two processes. The calculations were based on a previously reported anisotropic intermolecular potential including both the long-range multipole, induction, and dispersion forces and a short-range atom-atom model. It is shown that components with L₁ = 3 of the atom-atom model are dominant contributions to the diffusion operator. As a consequence, in comparison with other molecular systems such as the CH₃Cl-N₂ and CH₃ I-N₂ , theoretically predicted line coupling and line mixing effects exhibit completely new j and k dependencies. In general, the theoretically calculated halfwidths and intra-doublets’ off-diagonal elements of the relaxation matrix are in reasonable agreement with measurements.