scholarly journals The stereodynamics study on the isotopic substitution C + SH(D, T) → H(D, T) + CS reactions on the new HCS(X2A′ ) potential energy surface

2017 ◽  
Vol 95 (12) ◽  
pp. 1219-1224 ◽  
Author(s):  
Lu-Lu Zhang ◽  
Shou-Bao Gao ◽  
Yu-Zhi Song ◽  
Da-Guang Yue ◽  
Guo-Meng Chen ◽  
...  
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Cross Sections ◽  
Energy Surface ◽  
Substitution Effect ◽  
Classical Trajectory ◽  
Distribution Functions ◽  
Isotopic Substitution ◽  
Angle Distribution ◽  
Reagent Molecule

The quasi-classical trajectory calculations are carried out to investigate the isotopic substitution effect on title reactions based on the recently developed, accurate potential energy surface of the HCS(X2[Formula: see text]) (Song, Zhang, et al. Sci. Rep. 6, 37734 (2016)). The total integral cross sections (ICSs) and vibrational state resolved ICSs are obtained for C + SH(D, T) → H(D, T) + CS reactions. In addition, differential cross sections and two angle distribution functions P(θr), P([Formula: see text]) at different collision energies are investigated. It is found that the peaks of P(θr) and P([Formula: see text]) become lower with the reagent molecule SH turning into SD and ST.

INVESTIGATION OF THE EXCHANGE REACTION H + H′S → HS + H′ ON THE 1A′ STATE POTENTIAL ENERGY SURFACE

2013 ◽  
Vol 12 (04) ◽  
pp. 1350030
Author(s):  
LIN-BO JI ◽  
TING-XIAN XIE ◽  
HONG-YAN WANG
Keyword(s):  
Potential Energy ◽  
Wave Packet ◽  
Potential Energy Surface ◽  
Exchange Reaction ◽  
Dihedral Angle ◽  
Cross Sections ◽  
Energy Surface ◽  
Distribution Functions ◽  
Time Dependent ◽  
Angle Distribution

The quantum time dependent wave packet (TDWP) and quasiclassical trajectory (QCT) calculations were carried out to study the exchange reaction H(2S) + H′S(2Π) → HS(2Π) + H′(2S) on the 1A′ potential energy surface (PES). The integral cross sections of the H + H′S (v = j = 0) → HS + H′ reaction calculated by the two methods were presented. The results reveal that the integral cross sections (ICS) decrease with the collision energy increasing. The result of the QCT calculations is reasonably consistent with the time-dependent wave packet. Moreover, the differential cross sections (DCS) were calculated by the QCT method at the four different collision energies, which display a forward–backward symmetry. A long-lifetime H2S intermediate complex of the exchange reaction was found according to the trajectories. In the stereodynamics investigation, the polar and dihedral angle distribution functions were calculated, which have the distinct oscillations. The oscillations could be attributed to the deep well on the 1A′ PES. However, based on the polar-angle and dihedral angle distribution functions, it could be predicted that the main product rotational angular momentum preferentially point to the positive or negative direction of y-axes.

INFLUENCE OF THE COLLISION ENERGY ON STEREODYNAMICS OF THE F + LiH (v = 0, j = 0) → LiF + H REACTION

2011 ◽  
Vol 10 (04) ◽  
pp. 401-410
Author(s):  
TAO WANG ◽  
XIANGYANG MIAO
Keyword(s):  
Angular Momentum ◽  
Angular Distribution ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Dihedral Angle ◽  
Collision Energy ◽  
Energy Surface ◽  
Classical Trajectory ◽  
Angle Distribution ◽  
Title Reaction

The stereodynamics of the title reaction based on the ground 2A′ potential energy surface (PES) has been investigated using the method of the quasi-classical trajectory (QCT) at different collision energies (23 kcal/mol, 35 kcal/mol and 46 kcal/mol). The vector properties of the angular momentum (described by the distribution of K - J′P(θr), the dihedral angle distribution of K - K′ - J′P(φr) and the angular distribution P(θr, ϕr)) and the four PDDCSs [(2π/σ)(dσ00/dωt), (2π/σ)(dσ20/dωt), (2π/σ)(dσ22+/dωt), (2π/σ)(dσ21-/dωt)] of the product LiF at each collision energy have been presented, respectively. Further, the collision energy effects on the behavior of the product LiF have been discussed and studied.

Energy-dependent stereodynamics for the H(2S)+NH(X3)→H2(X1Σg+)+N(4S) reaction on the improved ZH potential energy surface

2013 ◽  
Vol 91 (6) ◽  
pp. 387-391 ◽  
Author(s):  
Cui-Xia Yao ◽  
Guang-Jiu Zhao
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Cross Sections ◽  
Energy Surface ◽  
Center Of Mass ◽  
Classical Trajectory ◽  
Rotational Alignment ◽  
Title Reaction ◽  
Calculation Results ◽  
Generalized Differential

In this work, quasi-classical trajectory (QCT) calculations have been first carried out for the title reaction on a new global potential energy surface for the lowest quartet electronic state, 4A″. The average rotational alignment factor [P2(j'·k)] as a function of collision energy and the two commonly used polarization dependent generalized differential cross sections PDDCS00, PDDCS20, have been calculated in the center-of-mass (CM) frame, separately. Three angular distributions, P(θr), P(φr), and P(θr, φr) are also calculated to gain insight into the alignment and the orientation of the product molecules. Calculations show that the average rotational alignment factor on the ZH PES is almost invariant with collision energies. The distributions of P(θr) and P(φr) derived from the title reaction indicate that the product polarization is strong. Validity of the QCT calculation has been examined and proven in the comparison with the quantum-wave-packet calculation results. Comparisons with available quasi-classical trajectory results are made and discussed.

Quasi-classical trajectory study of the O(1D) + HF reaction dynamics on 11A′ potential energy surface

2011 ◽  
Vol 89 (6) ◽  
pp. 650-656 ◽  
Author(s):  
Juan Zhao
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Collision Energy ◽  
Energy Surface ◽  
Theoretical Foundation ◽  
Singlet State ◽  
Reaction Dynamics ◽  
Classical Trajectory ◽  
Isotopic Substitution ◽  
Title Reaction

The quasi-classical trajectory (QCT) calculations for the title reaction were carried out using the recently developed, accurate potential energy surface (PES) of the [Formula: see text] singlet state of the OHF system The integral cross section and the product rotational alignment factor [Formula: see text] were calculated as a function of collision energy. In addition, I discovered the effect of isotopic substitution on stereodynamics for the title reaction, and the influence of the rotation excitation of the reagent on stereodynamics is also presented. Both the scalar and vector properties of the reaction O(1D) + HF → OH + F(2P) are studied in this paper. It was found that the reaction is mainly controlled by an indirect reaction mechanism, and that the deep noncollinear insertion HOF well has a great impact on the dynamics of the reaction. The conclusions drawn in this paper will draw from references to similar reactions, and provide a theoretical foundation for related experiments.

Effect of collision energy on cross sections and product alignments for the C(1D) + H2 (v = 0, j = 0) insertion reactions

2010 ◽  
Vol 88 (5) ◽  
pp. 453-457 ◽  
Author(s):  
Lihua Kang ◽  
Bin Dai
Keyword(s):  
Angular Momentum ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Cross Sections ◽  
Total Angular Momentum ◽  
Collision Energy ◽  
Energy Surface ◽  
Chem Phys ◽  
Classical Trajectory ◽  
Insertion Reactions

Quasi-classical trajectory (QCT) calculations of total reaction probabilities and vibrationally state-resolved reaction probabilities at total angular momentum J = 0 as a function of collision energy for the C(1D) + H2 (v = 0, j = 0) reactions have been performed on an ab initio potential-energy surface [ J. Chem. Phys. 2001, 115, 10701]. In addition, the integral cross sections as a function of collision energy have been carried out for the same reaction. The product rotational alignments have also been calculated, which are almost invariant with respect to collision energies.

Rotational de-excitations of C3H+ (1Σ+) by collision with He: new ab initio potential energy surface and scattering calculations

2020 ◽  
Vol 494 (4) ◽  
pp. 5675-5681 ◽  
Author(s):  
Sanchit Chhabra ◽  
T J Dhilip Kumar
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Ab Initio ◽  
Cross Sections ◽  
Energy Surface ◽  
Molecular Ions ◽  
Basis Set ◽  
Rate Coefficients ◽  
Close Coupling ◽  
Collisional Rate Coefficients

ABSTRACT Molecular ions play an important role in the astrochemistry of interstellar and circumstellar media. C3H+ has been identified in the interstellar medium recently. A new potential energy surface of the C3H+–He van der Waals complex is computed using the ab initio explicitly correlated coupled cluster with the single, double and perturbative triple excitation [CCSD(T)-F12] method and the augmented correlation consistent polarized valence triple zeta (aug-cc-pVTZ) basis set. The potential presents a well of 174.6 cm−1 in linear geometry towards the H end. Calculations of pure rotational excitation cross-sections of C3H+ by He are carried out using the exact quantum mechanical close-coupling approach. Cross-sections for transitions among the rotational levels of C3H+ are computed for energies up to 600 cm−1. The cross-sections are used to obtain the collisional rate coefficients for temperatures T ≤ 100 K. Along with laboratory experiments, the results obtained in this work may be very useful for astrophysical applications to understand hydrocarbon chemistry.

A quasi-classical trajectory study of the reagent initial rotation quantum state effect on the reaction He + T2+ → HeT+ + T using an improved ab initio potential energy surface

2012 ◽  
Vol 90 (2) ◽  
pp. 230-236 ◽  
Author(s):  
Ningjiu Zhao ◽  
Yufang Liu
Keyword(s):  
Angular Momentum ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Quantum Number ◽  
Relative Velocity ◽  
Energy Surface ◽  
Rotational Quantum Number ◽  
Chem Phys ◽  
Classical Trajectory ◽  
Positive Direction

In this work, we employed the quasi-classical trajectory (QCT) method to study the vector correlations and the influence of the reagent initial rotational quantum number j for the reaction He + T2+ (v = 0, j = 0–3) → HeT+ + T on a new potential energy surface (PES). The PES was improved by Aquilanti co-workers (Chem. Phys. Lett. 2009. 469: 26–30). The polarization-dependent differential cross sections (PDDCSs) and the distributions of P(θr), P([Formula: see text]r), and P(θr, [Formula: see text]r) are presented in this work. The plots of the PDDCSs provide us with abundant information about the distribution of the product angular momentum polarization. The P(θr) is used to describe the correlation between k (the relative velocity of the reagent) and j′ (the product rotational angular momentum). The distribution of dihedral angle P([Formula: see text]r) shows the k–k′–j′ (k′ refers to the relative velocity of the product) correlation. The PDDCS calculations illustrate that the product of this reaction is mainly backward scatter and it has the strongest polarization in the backward and sideways scattering directions. At the same time, the results of the P([Formula: see text]r) demonstrate that the product HeT+ tends to be oriented along the positive direction of the y axis and it tends to rotate right-handedly in planes parallel to the scattering plane. Moreover, the distribution of the P(θr) manifests that the product angular momentum is aligned along different directions relative to k. The direction of the product alignment may be perpendicular, opposite, or parallel to k. Moreover, our calculations are independent of the initial rotational quantum number.

Investigation of rotational state-changing collisions of C2N− ions with helium

2019 ◽  
Vol 15 (S350) ◽  
pp. 443-444
Author(s):  
Jan Franz ◽  
Francesco Antonio Gianturco
Keyword(s):  
Dipole Moment ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Cross Sections ◽  
Energy Surface ◽  
Inelastic Collisions ◽  
Atomic Gases ◽  
Molecular Anion ◽  
Helium Atoms ◽  
Molecular Anions

AbstractThe cross sections for rotational inelastic collisions between atoms and a molecular anion can be very large, if the anion has a dipole moment. This makes molecular anions very efficient in cooling atomic gases. We address rotational inelastic collisions of Helium atoms with the molecular anion C2N–. Here we present preliminary calculations of the potential energy surface.

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