STEREODYNAMICS AND ISOTOPE EFFECTS FOR THE REACTION N + NH → N2 + H

2012 ◽  
Vol 11 (01) ◽  
pp. 87-97 ◽  
Author(s):  
YINGYING CHEN ◽  
MEIYU ZHAO
Keyword(s):  
Cross Sections ◽  
Collision Energy ◽  
Energy Surface ◽  
Isotope Effects ◽  
Classical Trajectory ◽  
Many Body ◽  
Generalized Polarization ◽  
Dependency Relationship ◽  
Energy Dependency ◽  
Isotopic Effects

Quasi-Classical Trajectory (QCT) calculations have been carried out to study the stereodynamics of the reactions N + NH → N 2 + H and isotopic effects on the product polarization at collision energies of 10.0 kcal/mol and 25.0 kcal/mol which proceed on the Double-Many-Body-Expansion (DMBE) potential energy surface. The distribution of dihedral angle P(ϕr), and the distribution of angle between k and j′, P(θr) are discussed in detail. Furthermore, four generalized polarization dependent differential cross sections (PDDCSs) (2π/σ)(dσ00/dω), (2π/σ)(dσ20/dω), (2π/;σ)(dσ22+/dω), and (2π/σ)(dσ21 -∕dω) are presented. The results reveal that isotope effect plays an important role for P(ϕr) and P(θr) distribution, and the PDDCSs exhibit similar collision energy dependency relationship at low and high collision energies.

Reagent vibrational, rotational and isotopic effects on stereodynamics of the H + OCl → OH + Cl reaction

2014 ◽  
Vol 13 (01) ◽  
pp. 1450002
Author(s):  
Ruifeng Lu ◽  
Zhenyu Xu ◽  
Yunhui Wang
Keyword(s):  
Cross Sections ◽  
Collision Energy ◽  
Energy Surface ◽  
Vibrational Excitation ◽  
Classical Trajectory ◽  
Angular Distributions ◽  
Title Reaction ◽  
Generalized Polarization ◽  
Trajectory Method ◽  
Isotopic Effects

The quasi-classical trajectory method has been employed to investigate the initial vibrational and rotational effects of the title reaction on an improved ab initio potential energy surface for the 11A′ state. Meanwhile, isotopic effect has also been studied at collision energy of 19 kcal/mol. The product rotational alignment factor 〈P2(j′ • k)〉, angular distributions of P(ϕr), P(θr) and the generalized polarization dependent differential cross-sections have been calculated. The- results show that the reagent vibrational excitation generally strengthens the product alignment perpendicular to the reagent relative velocity vector k and affects the product scattering preference, and the rotational excitation has the same trend from j = 0 to 2 except for the higher excitation of j = 3. Further, the substitution of atom H with D leads to a stronger product alignment while changes some stereodynamical properties subtly.

QUASI-CLASSICAL TRAJECTORY STUDY OF THE REACTION N + NH (v = 0–3, j=0) → N2 + H

2013 ◽  
Vol 12 (03) ◽  
pp. 1350015 ◽  
Author(s):  
ZHENYU XU ◽  
YUNHUI WANG ◽  
RUIFENG LU
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Ground State ◽  
Collision Energy ◽  
Energy Surface ◽  
Vibrational Excitation ◽  
Classical Trajectory ◽  
Reaction Probability ◽  
Many Body ◽  
Generalized Polarization

The quasi-classical trajectory (QCT) calculations have been carried out for the reaction N + NH (v = 0–3, j=0) → N2 + H on the ground state of double many-body expansion (DMBE) potential energy surface [Caridade, PJSB, Poveda LA, Rodrigues SPJ, Varandas AJC, J Phys Chem A111:1172, 2007]. The influence of reagent vibrational excitation on reaction probability for total angular momentum J = 0 and integral cross section (ICS) at collision energies ranging from 0.1 eV to 1.0 eV has been investigated. The reaction probability tends to decrease with increasing collision energy and increase with the rising of initial vibration state, although some fluctuations appear. The ICS declines monotonously with the increase of collision energy and v. The product rotational alignment factor 〈P2(j′•k)〉 has also been calculated, and its value has a declining trend with the increase of collision energy. In spite of that, the results still show that the product is highly aligned. In addition, the vibrational excitation effect on the product polarization has also been studied. All the distributions of P(ϕr), P(θr), and the generalized polarization dependent differential cross sections indicate dependent behaviors on v.

THE STEREODYNAMICS STUDY OF THE C(3P) + OH (X2 Π) → CO(X1Σ+) + H(2S) REACTION

2010 ◽  
Vol 09 (05) ◽  
pp. 935-943 ◽  
Author(s):  
PENG SONG ◽  
YONG-HUA ZHU ◽  
JIAN-YONG LIU ◽  
FENG-CAI MA
Keyword(s):  
Angular Momentum ◽  
Cross Sections ◽  
Collision Energy ◽  
Energy Surface ◽  
Center Of Mass ◽  
Title Reaction ◽  
High Collision Energy ◽  
Dependency Relationship ◽  
Energy Dependency ◽  
Mass Frame

The stereodynamics of the title reaction on the ground electronic state X2A' potential energy surface (PES)1 has been studied using the quasiclassical trajectory (QCT) method. The commonly used polarization-dependent differential cross-sections (PDDCSs) of the product and the angular momentum alignment distribution, P(θr) and P(Φr), are generated in the center-of-mass frame using QCT method to gain insight of the alignment and orientation of the product molecules. Influence of collision energy on the stereodynamics is shown and discussed. The results reveal that the distribution of P(θr) and P(Φr) is sensitive to collision energy. The PDDCSs exhibit different collision energy dependency relationship at low and high collision energy ranges.

Theoretical study of the stereo-dynamics of the H + HeH+(v = 0, j = 0) → H2+ + He reaction

2010 ◽  
Vol 88 (12) ◽  
pp. 899-904 ◽  
Author(s):  
Juanjuan Lv ◽  
Xinguo Liu ◽  
Jingjuan Liang ◽  
Haizhu Sun
Keyword(s):  
Reaction Mechanism ◽  
Cross Sections ◽  
Collision Energy ◽  
Energy Surface ◽  
Theoretical Study ◽  
Classical Trajectory ◽  
Direct Reaction ◽  
Generalized Polarization ◽  
Product Molecule ◽  
Out Of Plane

Theoretical study of the stereo-dynamics of the reaction, H + HeH+ (v = 0,  j = 0) → H 2+  + He, have been performed with quasi-classical trajectory (QCT) method at different collision energies on a new ab initio potential energy surface. The distributions of P(θr), P(ϕr) and four generalized polarization-dependent differential cross-sections have been calculated. The results indicate that both the orientation and alignment of the rotational angular momentum are impacted by collision energies. With the collision energy increases, the rotation of the product molecule has a preference of changing from the “in-plane” reaction mechanism to the “out-of-plane” mechanism. Although the reaction is mainly dominated by the direct reaction mechanism, the indirect mechanism plays a role while the collision energy is very low.

Isotope Effect of the Stereodynamics for the Reactions N(4S)+HD→NH+D and N(4S)+HD→ND+H

2016 ◽  
Vol 878 ◽  
pp. 96-100
Author(s):  
Ya Hui Guo
Keyword(s):  
Isotope Effect ◽  
Cross Sections ◽  
Energy Surface ◽  
Chem Phys ◽  
Classical Trajectory ◽  
Angular Distributions ◽  
Many Body ◽  
Generalized Polarization ◽  
Trajectory Calculations ◽  
Phys Chem Chem Phys

Quasi-classical trajectory calculations have been employed to investigate the influence of isotope effect on the stereodynamics of the title reactions N(4S)+HD→NH+D and N(4S)+HD→ND+H on the 4A" double many-body expansion (DMBE) potential energy surface (PES) newly constructed by L. A. Poveda et al. [Phys. Chem. Chem. Phys. 7 (2005) 2867]. The generalized polarization-dependent differential cross sections (PDDCSs) and the three angular distributions of P(θr), P(φr) and P(θr,φr) are presented and discussed. It is revealed isotope effect exert a substantial influence on the product polarizations.

INFLUENCE OF VIBRATIONAL EXCITATION AND COLLISION ENERGY ON THE STEREO DYNAMICS OF THE REACTIONS: N(4S)+H2(v = 0-3,j = 0) → NH(X3Σ-)+H

2012 ◽  
Vol 11 (04) ◽  
pp. 763-780 ◽  
Author(s):  
YONG-JIANG YU ◽  
DE-HUA WANG ◽  
SHU-XIANG FENG ◽  
WEN-ZE XIA
Keyword(s):  
Cross Sections ◽  
Collision Energy ◽  
Energy Surface ◽  
Vibrational Excitation ◽  
Chem Phys ◽  
Classical Trajectory ◽  
Angular Distributions ◽  
Many Body ◽  
Initial State ◽  
Vector Correlations

Quasi-classical trajectory (QCT) calculations have been carried out to study the stereodynamics of the title reactions, using the double many-body expansion (DMBE) potential energy surface (PES) constructed by Poveda [Poveda LA, Varandas AJC, Phys. Chem. Chem. Phys.7:2867, 2005]. Vector correlations, such as the distributions of the polarization-dependent differential cross-sections (PDDCSs), the angular distributions of P(θr), P(ϕr), P(θr,ϕr), and the product alignment parameter P2( cos θr) are reported within the energy range of 25–140 kcal mol-1. The influences of the collision energy and the initial state-selected vibrational excitation are discussed in detail. In addition, Validity of the current QCT calculations is also examined and compared with the revelant results reported by Pascual et al. [Pascual RZ, Schatz GC, Lendvay G, Troya D, J. Phys. Chem. Aਠ106:4125, 2002].

The dynamics of the Br + HgBr (v = 0, j = 0) → Br2 + Hg reaction based on quasi-classical trajectory calculations

2018 ◽  
Vol 96 (8) ◽  
pp. 926-932 ◽  
Author(s):  
Guan-Qing Ren ◽  
Ai-Ping Fu ◽  
Shu-Ping Yuan ◽  
Tian-Shu Chu
Keyword(s):  
Angular Momentum ◽  
Cross Sections ◽  
Relative Velocity ◽  
Total Angular Momentum ◽  
Collision Energy ◽  
Energy Surface ◽  
Classical Trajectory ◽  
Title Reaction ◽  
Trajectory Calculations ◽  
Angular Momentum Quantum Number

To investigate the dynamics mechanism of the Br + HgBr → Br2 + Hg reaction, the quasi-classical trajectory calculations are performed on Balabanov’s potential energy surface (PES) of ground electronic state. Both the scalar and vector properties are investigated to recognize the dynamics of the title reaction. Reaction probability for the total angular momentum quantum number J = 0 is determined at the collision energies (denoted as Ec) in a range of 1–25 kcal/mol, and the product vibrational distributions are given and compared between Ec = 20 and 40 kcal/mol. Other calculation values characterizing product polarizations including polarization-dependent differential cross sections (PDDCSs), distributions of P(θr), P([Formula: see text]), and P(θr, [Formula: see text]), are all discussed and compared between the two different collision energies in detail to analyze the alignment and orientation characteristics. It is revealed that the products prefer forward scattering and the PDDCSs are anisotropic in the whole range of the scattering angle. The product rotational angular momentum j′ shows a tendency to align perpendicular to the reagent relative velocity k. In fact, the product polarization of the title reaction is weak at both collision energies. In terms of horizontal comparison, the alignment is slightly stronger but the orientation is even less remarkable at higher collision energy.

VECTOR CORRELATIONS AND PRODUCT POLARIZATIONS IN THE N(2D) + D2 → ND + D REACTIVE SYSTEM

2012 ◽  
Vol 11 (05) ◽  
pp. 1005-1018 ◽  
Author(s):  
SHANSHAN NIE ◽  
TIANSHU CHU
Keyword(s):  
Angular Distribution ◽  
Cross Sections ◽  
Energy Surface ◽  
Center Of Mass ◽  
Classical Trajectory ◽  
Reactive System ◽  
Angle Distribution ◽  
Polar Form ◽  
Generalized Polarization ◽  
Vector Correlations

The vector correlations between products and reagents of the N (2D) + D 2 reaction are investigated by employing quasi-classical trajectory (QCT) calculation on the accurate DMBE potential energy surface (PES) of the 2A″ state. Stereo-dynamic quantities, including the four generalized polarization-dependent differential cross-sections (PDDCSs), the angular distribution P(θr), the dihedral-angle distribution P(φr), as well as the product rotational angular distribution in the polar form of P(θr, φr), are calculated in the center-of-mass (CM) frame. The results indicate that the product rotational angular momentum j′ not only aligns along the y-axis, but also orients to the negative direction of the y-axis. The isotope effect in the context of chemical stereo-dynamics and influences of different versions of ground-state PESs on vector correlations are shown and discussed.

QUASI-CLASSICAL TRAJECTORY STUDY OF THE REACTION PROBABILITY AND CROSS SECTION OF THE REACTION LiH + H

2013 ◽  
Vol 12 (01) ◽  
pp. 1250093 ◽  
Author(s):  
YULIANG WANG ◽  
JINCHUN ZHANG ◽  
BAOGUO TIAN ◽  
KUN WANG ◽  
XIAORUI LIANG ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Ground State ◽  
Collision Energy ◽  
Energy Surface ◽  
Classical Trajectory ◽  
Reaction Cross ◽  
Reaction Probability ◽  
Title Reaction ◽  
Reaction Cross Sections

Based on the new accurate potential energy surface of the ground state of LiH2 system. Quasi-classical trajectory (QCT) calculations were carried out for the reaction LiH + H . The reaction probability of the title reaction for J = 0 has been calculated. The reaction cross sections were calculated as functions of the collision energy in the range 0.1–2.5 eV. The results were found to be well consistent with the previous real wave packet (RWP) and QCT results.

EFFECTS OF ROTATIONAL AND VIBRATIONAL EXCITATION ON THE STEREODYNAMICS OF THE O (D-1) + HCl → OH + Cl REACTION

2009 ◽  
Vol 08 (06) ◽  
pp. 1177-1184 ◽  
Author(s):  
QIANG WEI ◽  
VICTOR WEI-KEH WU ◽  
BO ZHOU
Keyword(s):  
Cross Sections ◽  
Collision Energy ◽  
Energy Surface ◽  
Vibrational Excitation ◽  
Classical Trajectory ◽  
Rotational Excitation ◽  
Title Reaction ◽  
Vibrational Excitations ◽  
Product Vector ◽  
Good Agreement

The stereodynamics of the title reaction on the ground 1 1A′ potential energy surface (PES) has been studied using quasi-classical trajectory (QCT) method. Collision energy of 6.4 kcal/mol is considered, and vector properties including angular momentum alignment distributions and polarization-dependent differential cross-sections (PDDCS) of the product OH are presented. Furthermore, the influence of reagent rotational excitation and vibrational excitation on the product vector properties has also been studied in the present work. The results indicate that the distribution of the P(θr) and P(ϕr) are sensitively affected by the rotational and vibrational excitation. The rotational excitation decreases the degree of alignment and orientation, while vibrational excitation increases the degree of alignment and orientation. The PDDCS (2π/σ)(dσ20/dωt) and (2π/σ)(dσ22+/dωt) are sensitively influenced by rotational and vibrational excitations, while the PDDCS ((2π/σ)(dσ00/dωt)) and (2π/σ)(dσ21-/dωt) are not. The preference of forward scattering has been found from the results of PDDCS ((2π/σ)(dσ00/dωt)), which is in good agreement with the experimental results.

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