Global analytical potential energy surfaces for HO2(X̃A″2) based on high-level <i>ab initio</i> calculations

Xie, Daiqian; Xu, Chuanxiu; Ho, Tak‐San; Rabitz, Herschel; Lendvay, György; Lin, Shi Ying; Guo, Hua

doi:10.1063/1.2446994

Cited by 48 publications

(52 citation statements)

References 70 publications

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“…We present in Fig. 1 [57,58], referred to as the XXZLG PES. The XX-ZLG PES has been used in a number of quantum dynamics calculations of the O + OH system at high collision energies [53,54,59].…”

Section: Methodology a Potential Energy Surfacesmentioning

confidence: 99%

Formation of molecular oxygen in ultracoldO+OHcollisions

2009

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We discuss the formation of molecular oxygen in ultracold collisions between hydroxyl radicals and atomic oxygen. A time-independent quantum formalism based on hyperspherical coordinates is employed for the calculations. Elastic, inelastic and reactive cross sections as well as the vibrational and rotational populations of the product O2 molecules are reported. A J-shifting approximation is used to compute the rate coefficients. At temperatures T = 10 − 100 mK for which the OH molecules have been cooled and trapped experimentally, the elastic and reactive rate coefficients are of comparable magnitude, while at colder temperatures, T < 1 mK, the formation of molecular oxygen becomes the dominant pathway. The validity of a classical capture model to describe cold collisions of OH and O is also discussed. While very good agreement is found between classical and quantum results at T = 0.3 K, at higher temperatures, the quantum calculations predict a larger rate coefficient than the classical model, in agreement with experimental data for the O + OH reaction. The zero-temperature limiting value of the rate coefficient is predicted to be about 6 × 10 −12 cm 3 molecule −1 s −1 , a value comparable to that of barrierless alkali-metal atom -dimer systems and about a factor of five larger than that of the tunneling dominated F + H2 reaction.

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Section: Methodology a Potential Energy Surfacesmentioning

confidence: 99%

Formation of molecular oxygen in ultracoldO+OHcollisions

2009

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“…Indeed, special care has been taken to achieve a realistic description of the atomdiatom long-range forces, through the inclusion of dispersion and electrostatic energy components. Although new surfaces have been reported (Xie et al, 2007) from high-level ab initio methods, they may not describe long-range forces adequately since they are based on interpolation schemes and rely on the accuracy of the raw data. In fact, despite having been published in 1990, DMBE IV remains amongst the reference potential energy surfaces (PESs) in the literature (Lin et al, 2006) for HO 2 ( 2 A ).…”

Section: The O + Oh(v) Reactionmentioning

confidence: 99%

Implications of the O + OH reaction in hydroxyl nightglow modeling

2013

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Abstract. The hydroxyl nightglow has been examined anew using calculated rate constants for the key reactive and inelastic O + OH(v ) quenching processes. These constants have been obtained from quasiclassical trajectories run on the adiabatic ab initio-based double many-body expansion-IV potential energy surface for the ground state of the hydroperoxil radical. Significant differences in the vertical profiles of vibrationally excited hydroxyl radicals are obtained relative to the ones predicted by Adler-Golden (1997) when employing an O + OH(v ) effective rate constant chosen to be twice the experimental value for quenching of OH(v = 1). At an altitude of 90 km, such deviations range from ∼ 80 % for v = 1 to only a few percent for v = 9. Other mechanisms reported in the literature have also been utilized, in particular those that loosely yield lower and upper limits in the results, namely sudden-death and collisional cascade. Finally, the validity of the steady-state hypothesis is analysed through comparison with results obtained via numerical integration of the master equations.

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“…Due to its importance, the reaction has been the subject of a large number of studies, both experimental and theoretical. 2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27 A large body of information is available on the reaction of H atoms with oxygen molecules in the electronic ground state,…”

Section: Introductionmentioning

confidence: 99%

A Quasiclassical Trajectory Study of the Reaction of H Atoms with O₂(¹Δ_g)

Szabó

Lendvay

2015

J. Phys. Chem. A

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The kinetic and dynamic characteristics of the reaction of H atoms with electronically excited O 2 were studied using the quasiclassical trajectory (QCT) method and the potential energy surface of Li et al. (J. Chem. Phys. 2010, 133, 144306-144314.). The reaction takes place via a deep potential well that can be entered by climbing a barrier in the reactant valley and can be left without a barrier on the product side. In this reaction the basic assumptions of statistical rate theories are not fulfilled: i) 80% of the trajectories cross the barrier region twice and are nonreactive; b) The energy is not equilibrated in the HO 2 potential well. The QCT cross sections agree well with those from the existing exact quantum mechanical data and extend them to vib-rotationally excited reactants. The thermal rate coefficients agree well with measurements of pure reactive quenching of O 2 ( 1 Δ g ) and are 2 lower than those involving both reactive and electronic quenching. The temperature dependence is described as k 2 = 5.81×10 -16 T 1.45 exp(-2270/T) cm 3 molecule -1 s -1 . Based on comparison of the QCT data with the two kinds of experiments we estimate that electronic quenching is faster than reaction by a factor of about 10 at low and 2 at high flame temperatures.

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Global analytical potential energy surfaces for HO2(X̃A″2) based on high-level ab initio calculations

Cited by 48 publications

References 70 publications

Formation of molecular oxygen in ultracoldO+OHcollisions

Formation of molecular oxygen in ultracoldO+OHcollisions

Implications of the O + OH reaction in hydroxyl nightglow modeling

A Quasiclassical Trajectory Study of the Reaction of H Atoms with O₂(¹Δ_g)

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Global analytical potential energy surfaces for HO2(X̃A″2) based on high-level ab initio calculations

Cited by 48 publications

References 70 publications

Formation of molecular oxygen in ultracoldO+OHcollisions

Formation of molecular oxygen in ultracoldO+OHcollisions

Implications of the O + OH reaction in hydroxyl nightglow modeling

A Quasiclassical Trajectory Study of the Reaction of H Atoms with O2(1Δg)

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A Quasiclassical Trajectory Study of the Reaction of H Atoms with O₂(¹Δ_g)