Rotational excitation of CO2 induced by He: New potential energy surface and scattering calculations
Résumé
The CO2 molecule is of great interest for astrophysical studies since it can be found in a large variety of astrophysical media where it interacts with the dominant neutral species, such as He, H2, or H2O. The CO2-He collisional system was intensively studied over the last two decades. However, collisional data appear to be very sensitive to the potential energy surface (PES) quality. Thus, we provide, in this study, a new PES of the CO2-He van der Waals complex calculated with the coupled-cluster method and a complete basis set extrapolation in order to provide rotational rate coefficients that are as accurate as possible. The PES accuracy was tested through the calculations of bound state transition frequencies and pressure broadening coefficients that were compared to experimental data. An excellent agreement was globally found. Then, revised collisional data were provided for the 10-300 K temperature range. Rate coefficients were compared to previously computed ones and are found to be up to 50% greater than previously provided ones. These differences can induce non-negligible consequences for the modeling of CO2 abundance in astrophysical media. © 2022 Author(s).
Mots clés
Rate coefficients
Potential-energy surfaces
Neutral species
Coupled clusters methods
Complete basis sets
Collisional system
Collisional
Van der Waals forces
Quantum chemistry
Potential energy surfaces
Potential energy
Numerical methods
Molecular physics
Carbon dioxide
Rotational excitation
Scattering calculations
Van der Waals complex
Astrophysics
Quantum dynamics
Atomic and molecular collisions
Domaines
Physique [physics]
Fichier principal
Godard et al-2022-Rotational excitation of CO2 induced by He.pdf (3 Mo)
Télécharger le fichier
Godard_pes_routine.zip (877.66 Ko)
Télécharger le fichier
Origine | Fichiers produits par l'(les) auteur(s) |
---|