Computation of orbiting cross-sections from ab initio potential energy surfaces for recombination of atomic oxygen

Chaithanya Kondur, Sharanya Subramaniam, Tzu Jung Pan, Kelly A. Stephani

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Recombination of atomic oxygen to O2 can be modeled within the direct simulation Monte Carlo (DMSC) framework using the two-step binary collision model (TSBC). Formation of an orbiting pair, (OP) is the first step in the TSBC recombination process, where two O atoms revolve around their common center of mass. So far, the OP formation cross-section has been obtained assuming detailed balance between the dissociated O atoms and the O2 molecule, without any regards to the physical nature of orbiting pairs. However, preliminary calculations reveal that an OP formation depends on collisional parameters like interaction impact parameter and relative translational energy. In the present work, we therefore compute OP formation cross-section and OP lifetimes based on classical scattering theory, and compare them with those obtained using (quasi-)classical trajectory calculations. These values are employed in computing the recombination rate coefficient for O2 formation from O+O+O interactions. A good agreement is obtained between the present calculations and recombination rate coefficient values computed by applying detailed balance to dissociation cross-section values obtained from QCT calculations.

Original languageEnglish (US)
Title of host publicationAIAA Scitech 2019 Forum
PublisherAmerican Institute of Aeronautics and Astronautics Inc, AIAA
ISBN (Print)9781624105784
StatePublished - 2019
EventAIAA Scitech Forum, 2019 - San Diego, United States
Duration: Jan 7 2019Jan 11 2019

Publication series

NameAIAA Scitech 2019 Forum


ConferenceAIAA Scitech Forum, 2019
Country/TerritoryUnited States
CitySan Diego

ASJC Scopus subject areas

  • Aerospace Engineering


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