Quasiclassical Kinetics of the H<sub>2</sub> + H<sub>2</sub> Reaction and Dissociation

Ceballos, Antonio; Garcı́a, Ernesto; Rodriguez, Arnulfo; Laganá, Antonio

doi:10.1021/jp002727f

Cited by 19 publications

(21 citation statements)

References 19 publications

(29 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, most theoretical dynamics studies have been performed using reduced dimensional or fulldimensional classical or quasi-classical trajectories (QCT) (Refs. [30][31][32][33][34][35][36][37][38] and reduced dimensional quantum mechanical (QM) methods. 29,[39][40][41][42][43][44] Lu et al 45 carried out the first accurate full-dimensional QM calculations of the H 2 + H 2 reaction using the time-dependent wave packet method.…”

Section: Introductionmentioning

confidence: 99%

Fully converged integral cross sections of collision induced dissociation, four-center, and single exchange reactions, and accuracy of the centrifugal sudden approximation in H2 + D2 reaction

Song

Lee

2012

The Journal of Chemical Physics

View full text Add to dashboard Cite

The initial state selected time-dependent wave packet method was employed to calculate the integral cross sections for the H(2) + D(2) reaction with and without the centrifugal sudden (CS) approximation by including all important K (the projection of the total angular momentum on the body-fixed axis) blocks. With a full-dimensional model, the first fully converged coupled-channel (CC) cross sections for different competitive processes from the ground rotational state were obtained: collision induced dissociation (CID), four-center (4C) reaction and single exchange (SE) reaction. The effect of the total angular momentum J on the reaction dynamics of H(2) + D(2) and the accuracy of the CS approximation have also been studied. It was found that the CID and SE processes occur in a wide range of J values while the 4C process can only take place in a narrow window of J values. For this reason, the CC cross section for the 4C channel is merely comparable to the SE channel. A comparison of the integral cross sections from CC and CS calculations showed that the CS approximation works well for the CID process but not for the 4C and SE processes, and the discrepancy between the CC and CS cross sections grows larger as the translational energy and/or the vibrational energy increase(s).

show abstract

Section: Introductionmentioning

confidence: 99%

Fully converged integral cross sections of collision induced dissociation, four-center, and single exchange reactions, and accuracy of the centrifugal sudden approximation in H2 + D2 reaction

Song

Lee

2012

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…In particular, our group studied the dynamics and the kinetics of H 2 + H 2 using both the full dimensionality and the reduced dimensionality trapezoidal model to compare with quantum results. 32,33 The mechanisms of the exchange and of the dissociation processes were investigated also for the isotopic variants H 2 + HD and H 2 + D 2 . 34 Finally, state-to-state rate coefficients for the CID, 4C, and SE processes for several combinations of initial vibrational states at temperatures of 1000, 2000, and 4000 K were also computed.…”

Section: Introductionmentioning

confidence: 99%

Effect of the Total Angular Momentum on the Dynamics of the H₂ + H₂ System

et al. 2009

View full text Add to dashboard Cite

Extended full-dimensional quasiclassical trajectory calculations have been performed for the H(a)H(b) (v(ab) = 10, 11, 12, 13, 14, j(ab) = 0) + H(c)H(d) (v(cd) = 0, j(cd) = 0) collisions at values of the translational energy ranging from threshold to 1.5 eV and values of the total angular momentum quantum number J varying from zero to very large ones. Collision-induced dissociation, four-center exchange reaction, and single exchange process probabilities have been calculated. Full-dimensional classical calculations were found to reproduce well the corresponding (J = 0) quantum results, including the thresholds. In contrast, the agreement of full-dimensional classical calculations with the corresponding both quantum and classical reduced dimensionality ones was found to be poor. The effect of varying J on the efficiency of the various processes has also been investigated. Four-center reactions were found to be favored by low values of J, whereas dissociation processes were found to be favored by higher values of J, as expected from the fact that energy exchange takes place at longer range than mass exchange. To evaluate to what extent the J = 0 full-dimensional calculations represent the unconstrained dynamics of the system, J-shift model classical results were compared with the all-J ones. Product vibrational distributions for both partially dissociative and exchange processes were also found to depend significantly on the value of J.

show abstract

“…It should be mentioned that several other dynamical studies on H 2 þ H 2 have been published recently, mainly using the quasiclassical trajectory method within a reduced dimensionality model [10,12,13] or in fulldimensional calculations [1,10,[14][15][16]. It is worth mentioning here the work of Ceballos et al [10], who compared full and reduced dimensionality (using the model of figure 1) quasiclassical trajectory calculations.…”

Section: Introductionmentioning

confidence: 99%

Wave packet calculations for H₂+H₂collisions: isotopic substitution effects

Hernández¹,

Campos‐Martínez²,

Caillie³

et al. 2004

Molecular Physics

View full text Add to dashboard Cite

Isotopic substitution effects for H 2 ðv 1 ¼ high) þ H 2 ðv 2 ¼ low) collisions are studied by means of time-dependent wave packet calculations. A three degree-of-freedom reduced dimensionality model was employed, which can account for collision-induced dissociation as well as for four centre exchange processes, for reactants in selected vibrational states. Mass effects are studied in two ways: by substituting the collider H 2 ðv 2 ¼ low) by D 2 in the same vibrational state, or by substituting the target H 2 ðv 1 ¼ high) by D 2 in a state with a similar vibrational energy. For the collider in its ground vibrational state, we have found that four centre probability profiles are quite similar but, conversely, thresholds for dissociation probabilities are quite different for the different mass combinations. The H 2 ðv 1 ¼ highÞ þ D 2 ðv 2 ¼ low) combination was found to be the most effective one for the dissociation process. In addition, the process of dissociation of the vibrationally cold diatom was found to be quite important in H 2 ðv 1 ¼ 14Þ þ D 2 ðv 2 ¼ 1, 2) collisions. These effects are analysed by means of plots of the potential energy surface using mass-scaled coordinates.

show abstract

Quasiclassical Kinetics of the H₂ + H₂ Reaction and Dissociation

Cited by 19 publications

References 19 publications

Fully converged integral cross sections of collision induced dissociation, four-center, and single exchange reactions, and accuracy of the centrifugal sudden approximation in H2 + D2 reaction

Fully converged integral cross sections of collision induced dissociation, four-center, and single exchange reactions, and accuracy of the centrifugal sudden approximation in H2 + D2 reaction

Effect of the Total Angular Momentum on the Dynamics of the H₂ + H₂ System

Wave packet calculations for H₂+H₂collisions: isotopic substitution effects

Contact Info

Product

Resources

About

Quasiclassical Kinetics of the H2 + H2 Reaction and Dissociation

Cited by 19 publications

References 19 publications

Fully converged integral cross sections of collision induced dissociation, four-center, and single exchange reactions, and accuracy of the centrifugal sudden approximation in H2 + D2 reaction

Fully converged integral cross sections of collision induced dissociation, four-center, and single exchange reactions, and accuracy of the centrifugal sudden approximation in H2 + D2 reaction

Effect of the Total Angular Momentum on the Dynamics of the H2 + H2 System

Wave packet calculations for H2+H2collisions: isotopic substitution effects

Contact Info

Product

Resources

About

Quasiclassical Kinetics of the H₂ + H₂ Reaction and Dissociation

Effect of the Total Angular Momentum on the Dynamics of the H₂ + H₂ System

Wave packet calculations for H₂+H₂collisions: isotopic substitution effects