A quantum wave-packet study of intersystem crossing effects in the O(P2,1,3,D21)+H2 reaction

Chu, Tian Shu; Zhang, Xin; Han, Kai

doi:10.1063/1.1924507

Cited by 85 publications

(79 citation statements)

References 24 publications

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“…+ H2, D2, and HD as well as for other systems have been studied with QM scattering methods 4,5 and quasiclassical trajectory surface hopping (TSH) method, 3 of which Han and co-workers 18,21 firstly introduced the benchmark non-adiabatic time-dependent quantum wave packet approach to study non-adiabatic dynamics of chemical reaction. On the theoretical side, Song and Gislason 23 studied the effect of reagent vibration and rotation on the reaction of O+H2 (v = 0, 1, 2; j) using quasiclassical calculations on Johnson-Winter potential energy surface.…”

Section: Introductionmentioning

confidence: 99%

Effects of Reagent Rotation on Stereodynamics Information of the Reaction O(1

Kuang¹,

Chen²,

Zhang³

et al. 2010

Bulletin of the Korean Chemical Society

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Quasiclassical trajectory (QCT) method has been used to investigate stereodynamics information of the reaction O( 1 D)+H2 → OH+H on the DK (Dobbyn and Knowles) potential energy surface (PES) at a collision energy of 23.06 kcal/ mol, with the initial quantum state of reactant H2 being set for v = 0 (vibration quantum number) and j = 0-5 (rotation quantum number). The PDDCSs (polarization dependent differential cross sections) and the distributions of P(θr), P(ør), P(θr, ør) have been presented in this work. The results demonstrate that the products are both forward and backward scattered. As j increases, the backward scattering becomes weaker while the forward scattering becomes slightly stronger. The distribution of P(θr) indicates that the product rotational angular momentum j′ tends to align along the direction perpendicular to the reagent relative velocity vector k, but this kind of product alignment is found to be rather insensitive to j. Furthermore, the distribution of P(ør) indicates that the rotational angular momentum vector of the OH product is preferentially oriented along the positive direction of y-axis, and such product orientation becomes stronger with increasing j.

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Section: Introductionmentioning

confidence: 99%

Effects of Reagent Rotation on Stereodynamics Information of the Reaction O(1

Kuang¹,

Chen²,

Zhang³

et al. 2010

Bulletin of the Korean Chemical Society

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show abstract

“…19,20 Dobbyn 25−28 In this work, a nonadiabatic quantum dynamics calculation was carried out based on the above PESs to obtain the product branching ratio of OH( 2 Π 3/2 ) to OH( 2 Π 1/2 ), which can be compared directly to experimental measurement. In two previous relevant studies, 27,28 the diabatic representation was used as asymptotic reactants and throughout in the whole calculation to produce the interested dynamical quantities including the product fine-structure ratio. However, the results generated in this way cannot be compared directly with experiment observables.…”

Section: Introductionmentioning

confidence: 99%

Adiabatic/Nonadiabatic State-to-State Reactive Scattering Dynamics Implemented on Graphics Processing Units

Zhang

Han

2013

J. Phys. Chem. A

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An efficient graphics processing units (GPUs) version of time-dependent wavepacket code is developed for the atom−diatom state-to-state reactive scattering processes. The propagation of the wavepacket is entirely calculated on GPUs employing the split-operator method after preparation of the initial wavepacket on the central processing unit (CPU). An additional split-operator method is introduced in the rotational part of the Hamiltonian to decrease communication of GPUs without losing accuracy of state-to-state information. The code is tested to calculate the differential cross sections of H + H 2 reaction and state-resolved reaction probabilities of nonadiabatic triplet−singlet transitions of O( 3 P, 1 D) + H 2 for the total angular momentum J = 0. The global speedups of 22.11, 38.80, and 44.80 are found comparing the parallel computation of one GPU, two GPUs by exact rotational operator, and two GPU versions by an approximate rotational operator with serial computation of the CPU, respectively. INTRODUCTIONA state-to-state quantum reaction dynamics study provides the most detailed observables and offers profound insight of chemical reaction process. In the past decades, several approaches for quantum reaction dynamics have been developed. With hyperspherical coordinate, the time-independent (TID) coupled-channel method has been employed to study many triatomic systems. 1,2 On the other hand, the timedependent method has been wildly used and implemented by different schemes because it does not scale as a cube of the number of basis functions. The coordinates can be chosen as reactant Jacobi, product Jacobi, or hyperspherical coordinates. 3−5 The wavepacket can be real or complex 6,7 and be propagated by the split-operator method, 8,9 Chebyshev polynomial expansion, finite difference approaches, and so forth. 10,11 While the calculations of differential cross sections (DCSs) have been reported for many triatomic reactions and two tetraatomic systems up to now, 12 theoretical calculations are still a great challenge of computational time consumption. Thus, the parallelism on central processing units (CPUs) has become a routine for state-resolved quantum dynamics. Because largescale parallelism with hundreds of computational nodes is still expensive, parallelism on graphics processing units (GPUs) provides a good alternative for being able to access hundreds of cores in the single GPU. The GPU has been widely used in many traditional computational scientific areas. As to chemistry science, one GPU provides hundreds of times the performance of a single CPU core in molecular dynamics and electronic structure calculations. 13,14 Recently, the CPUs/GPUs implemented in the TID method show a 6.98 speedup obtained by three GPUs and three CPU cores on computational efficiency. 15 Pacifici et al. have reported a GPU implementation for reactive scattering through the evaluation of the reactive

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“…More recently and related to the title reaction and to the nonadiabatic effects, Chu et al [55] reported an exact quantum wave-packet study of intersystem crossing effects for the O ( 3 P 2,1,0 , 1 D 2 ) + H 2 reaction, in which three triplets,ã 3 A ,b 3 A andã 3 A , and one singlet,X 1 A , electronic states were employed.…”

Section: Quantum Calculationsmentioning

confidence: 99%

“…Most recently, Maiti and Schatz [54] and Chu et al [55] have studied the intersystem crossing effects between the triplet and singlet states. Mainly focused on the O ( 3 P) + H 2 reaction, they found a negligible contribution to this reaction.…”

Section: Characterization Of the O ( 1 D) + H 2 Reactionmentioning

confidence: 99%