Rotational (de)-excitation of C5 by collision with He at low temperature

Autor:	A Chefai, Kamel Hammami, F. Khadri, M. Ben Khalifa
Rok vydání:	2021
Předmět:	Physics Scattering Molecular cloud General Physics and Astronomy Interstellar medium symbols.namesake Potential energy surface Radiative transfer symbols Physical and Theoretical Chemistry Atomic physics van der Waals force Collisional excitation Excitation
Zdroj:	Physical Chemistry Chemical Physics. 23:23741-23747
ISSN:	1463-9084 1463-9076
DOI:	10.1039/d1cp02652f
Popis:	An appropriate estimation of the abundance of the observed C5 radical in the interstellar medium requires accurate radiative and collisional rate coefficients. We present the first two-dimensional potential energy surface (2D-PES) for the ground electronic state of the C5(X1Σ+)–He(X1S) van der Waals system, obtained using an explicitly correlated coupled-cluster method with single, double, and perturbative triple excitations (RCCSD(T)-F12). This PES is subsequently used in quantum close-coupling (CC) scattering calculations. Collisional excitation cross-sections of the rotational levels of C5 by He were calculated for energies up to 1500 cm−1 using the standard (CC) method. The thermal dependence of the corresponding rate coefficients is given for the low and moderate temperature T ≤ 300 K regime of interstellar molecular clouds. This is the first study on the collisional rate coefficients for this system and may have important implications for the astrophysical detection of C5(X1Σ+) and modeling of carbon-rich media.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::ce21a9b1ed5456f08412ac94c4a2811e https://doi.org/10.1039/d1cp02652f Zobrazit plný text záznamu