AUTHOR=Hashemi S. Rasoul , Barinovs Girts , Nyman Gunnar TITLE=A ReaxFF molecular dynamics and RRKM ab initio based study on degradation of indene JOURNAL=Frontiers in Astronomy and Space Sciences VOLUME=10 YEAR=2023 URL=https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2023.1134729 DOI=10.3389/fspas.2023.1134729 ISSN=2296-987X ABSTRACT=

The degradation of indene is investigated using molecular dynamics (MD) with the ReaxFF force field and RRKM theory. Microcanonical rate constants are obtained over a broad energy range (8–25 eV). There is agreement between the results of the molecular dynamics and RRKM calculations at the lower energies, while the molecular dynamics rate constants are larger at the higher energies. At the lower energies there is also agreement with values obtained by using expressions for photodegradation of polyaromatic hydrocarbons from the literature. Values from those expressions however increase even faster with energy than our molecular dynamics rate constants do. At the same time those values are lower than an experimental result at 6.4 eV. This suggests that astrochemical models employing those values may result in unreliable polycyclic aromatic hydrocarbons abundances.