Simulation of argon induced coupling coefficients of NH$_3$ doublets and their speed dependence

Franck Thibault (1) , Alexandra Viel (1) , Christian Boulet (2)

1 IPR - Institut de Physique de Rennes
2 ISMO - Institut des Sciences Moléculaires d'Orsay

We present a theoretical evaluation of collision induced effects on a few typical doublets in the nu_4 band of ammonia perturbed by argon. Quantum dynamical calculations performed on two NH_3-Ar potential energy surfaces provide pressure broadening and intradoublet generalized cross sections. From these calculations we derive thermally averaged values at various temperatures. The intradoublet coupling terms at room temperature are found to be in good agreement with available data in the literature. In addition, we study the speed dependence of the pressure broadening and intradoublet coupling coefficients. The former show a usual speed dependence, quite important, but the later show a weak speed dependence at least around 296 K and above.

Mots clés: Line-shape parameters; Molecular physics; Quantum dynamics; Atomic and molecular collisions

Domaines: Physique [physics]

Franck Thibault, Alexandra Viel, Christian Boulet. Simulation of argon induced coupling coefficients of NH$_3$ doublets and their speed dependence. Journal of Quantitative Spectroscopy and Radiative Transfer, 2023, 296, pp.108453-1-12. ⟨10.1016/j.jqsrt.2022.108453⟩. ⟨hal-03880274⟩