Theoretical analysis of reactions related to the HNO2 energy surface: OH + NO and H + NO2 Original Research Article

The reactions occurring on the lowest singlet potential energy surface (PES) of the HNO2 system, including the H + NO2 and OH + NO entry channels, have been studied using ab initio molecular orbital (MO) and density functional (DFT) theories. The energetic and molecular parameters derived from coupled cluster singles and doubles with triples correction (CCSD(T)) and the B3LYP-DFT calculations using the 6-311++G(3df,2p) basis set, based on their respective optimised geometries obtained respectively, with a 6-31G(d,p) and 6-311++G(d,p) basis sets, have then been utilized to compute the rate constants of the different competitive channels in the HNO2 system within the framework of a quantum version of Rice-Ramsperger-Kassel theory (QRRK) and a canonical variational transition state theory (CVTST). Various thermochemical parameters of the [HNO2] species have also been computed.