IBER 2023

C5N− in collision with He: rotational transitions in the ISM

6 Sept 2023, 18:35

1h

Department of Physics, University of Coimbra

Poster Communication Poster Session

Speaker

Lola Gonzalez Sanchez (Universidad de Salamanca)

Description

In the last years, several C-bearing and (C,N)-bearing chains of molecular anions have been detected in the interestellar medium (ISM). Since experimental treatments are still challenging, computational methods have to be used to understand their chemistry. The C${}_5$N${}^{-}$ anion is one of the largest (C,N)-bearing chains and, although there are several theoretical studies [1-3] that describe the dynamics of the smaller (CN${}^{-}$,C${}_3$N${}^{-}$) + He/H${}_2$ systems, for the moment there has been no study reported for the collision between this molecular anion with He or H${}_2$.
We have performed quantum scattering calculations using a new ab initio potential energy surface (PES) where the interaction potential between C${}_5$N${}^{-}$ and He was obtained using CCSD(T) approach and the complete basis set (CBS) limit (see Figure 1). Given the ISM conditions of this system, we calculate the state-to-state (de-)excitation cross sections and the respective rate coefficients as a function of temperature. These results have been also compared by those obtained for the C${}_3$N${}^{-}$/C${}_5$N${}^{-}$ + H${}_2$ system.

Presentation materials

abstract_iber2023.pdf