Abstract
The importance of tunnelling in the formation of CO2 from O( 3 P) + CO at very low temperatures is studied with harmonic quantum transition state theory. To optimize the quantum transition state, we have used both fitted potential energy surfaces and direct dynamics, where forces and energies are calculated by a quantum chemistry code on the fly as they are needed. Whilst tunnelling does increase the classical reaction rate for the O( 3 P) + CO addition reaction at very low temperatures, the onset of tunnelling is at too low temperatures for the reaction to significantly contribute to the formation of interstellar CO2. Instead, it is more likely that an oxygen atom impinging on an interstellar ice would form a loosely bound complex with adsorbed CO, which may subsequently react with a hydrogen atom to ultimately yield CO2.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
