CO₂ Vibrational State Distributions From Quasi-Classical Trajectory Studies of the HO + CO → H + CO₂ Reaction and H + CO₂ Inelastic Collision

Abstract

Quasi-classical trajectory studies have been carried out for the HO + CO → H + CO2 reaction and H + CO2 inelastic collision on a recently developed global potential energy surface based on a large number of high-level ab initio points. The CO2 vibrational state distributions for these processes have been determined using an original normal-mode analysis method. It was found that the CO2 product of the reaction is highly excited in both the Fermi-linked bending and symmetric stretching modes, but little population was found in the antisymmetric stretching mode. The substantial excitation of the CO2 vibration, while consistent with the geometry of the transition state in the exit channel, is in disagreement with available experimental data. For the inelastic collision, the CO2 is much less excited despite much higher total energies. In addition, excitations in all vibrational modes were found, in good agreement with experiment.

Mode Specificity and Product Energy Disposal in Unimolecular Reactions: Insights from the Sudden Vector Projection Model

“…These observations are consistent with the SVP values in Table . Furthermore, the SVP model predicts that the stretching and bending modes of the CO 2 product are excited, which is consistent with both experimental , and theoretical observations. − …”

Analytic energy-level densities of separable harmonic oscillators including approximate hindered rotor corrections

“…Stationary points of the reaction network are well-described Previous studies on CO +ȮH mainly focused on evaluating the potential energy surface (PES) of the CO +ȮH reaction network. [29][30][31][32][33] Yu et al 29 used full coupled-cluster (FCC) and complete basis set (CBS) extrapolations at the CCSD(T)/cc-pVTZ level of theory for updating the PES. Recently, Li et al 30 proposed a PES based on approximately 35000 ab initio points at the CCSD(T)-F12/aug-cc-pVTZ level of theory.…”

Semiclassical transition state theory/master equation kinetics of HO + CO: Performance evaluation

“…Theoretical work on this reaction system is so extensive that it cannot be reviewed compactly; instead, to provide access to the literature, we will cite only a few papers. The theoretical work on the HOCO system includes the calculation of optimized stationary points on the potential energy surface (PES) at many levels of theory, [5][6][7] fulldimensional PESs constructed using various methods, 8 classical trajectory calculations, [9][10][11] and quantum dynamics calculations. [12][13][14][15] Rate constants, both canonical (ie, thermal) and microcanonical, 16 both with and without quantum tunneling, 17 have been calculated using transition state theory (TST), semiclassical TST (SCTST), 18,19 and ring polymer molecular dynamics.…”