THEORETICAL STUDY OF STEREODYNAMICS AND ISOTOPIC EFFECTS FOR THE REACTION C(3P) + OD(X2Π) → CO(X1Σ+) + D(2S)

2011 ◽  
Vol 10 (04) ◽  
pp. 447-469 ◽  
Author(s):  
RUNZE LIU ◽  
YIJUE DING ◽  
CHENGYUAN WEN ◽  
JINFENG LI ◽  
MINGWANG ZHONG ◽  
...  

Theoretical study on stereodynamics for the title reaction as well as its isotopic effects has been studied via QCT calculations on the ground X2A′ state of ab initio potential energy surface according to the study by Zanchet et al. Four polarization-dependent generalized differential cross-sections PDDCSs ((2π/σ) (dσ00/dωt), (2π/σ)(dσ20/dωt)), (2π/σ)(dσ22+/dωt), (2π/σ)(dσ21-/dωt), and the distributions of P(θr) and P(φr) that denotes the correlations of k-j′ and k-k′-j′ are presented in this work. Product angular distribution and rotational polarization have been analyzed at different collision energies and compared with C+OH reaction. Product angular distribution shows strong forward scattering at low collision energy and becomes more symmetric with forward and backward scattering with the increasing collision energy. The alignment and orientation of product angular momentum presents a different behavior with collision energy, the former one increases monotonically with collision energy, whereas the latter one shows first decreasing and then increasing behavior, which have been analyzed in the present paper. Product rotational polarization for C+OD is weaker than that for C+OH , which is mainly due to the mass factor and zero point energy of C+OD .

2013 ◽  
Vol 12 (02) ◽  
pp. 1250110
Author(s):  
YA-HUI GUO ◽  
FENG-YUN ZHANG

Utilizing the quasiclassical trajectory method, the product rotational polarization of the reaction N(4S) + D2 → ND + D has been calculated at different collision energies on the DMBE potential energy surface [Poveda LA et al., Phys Chem Chem Phys7:2867, 2005]. The distribution of the angle between k and j′, P(θr), the distribution of dihedral angle denoting k–k′–j′ correlation, P(ϕr), as well as the angular distribution of product rotational vectors in the form of polar plots P(θr, ϕr) are calculated. In addition, the four commonly used polarization-dependent differential cross sections, dσ00/dωt, dσ20/dωt, dσ22+/dωt, and dσ21-/dωt with ωt being the polar coordinates of the product velocity k′, are calculated in the center-of-mass frame. The effects of the collision energy on the product polarization are presented and discussed. In comparison with the result of Yu et al. [Yu YJ et al., Chin Phys B20:123402, 2011], significant isotope effects on the stereodynamics of N(4S) + D2(H2) → ND(H) + D(H) have also been revealed.


2014 ◽  
Vol 13 (01) ◽  
pp. 1450002
Author(s):  
Ruifeng Lu ◽  
Zhenyu Xu ◽  
Yunhui Wang

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.


2019 ◽  
Vol 15 (S350) ◽  
pp. 114-115
Author(s):  
K. P. Bowen ◽  
P.-M. Hillenbrand ◽  
J. Liévin ◽  
X. Urbain ◽  
D. W. Savin

AbstractH2D+ and D2H+ are important chemical tracers of prestellar cores due to their pure rotational spectra that can be excited at the ~20 K temperature of these environments. The use of these molecules as probes of prestellar cores requires understanding the chemistry that forms and destroys these molecules. Of the eight key reactions that have been identified (Albertssonet al. 2013), five are thought to be well understood. The remaining three are the isotope exchange reactions of atomic D with H $${ + \over 3}$$ , H2D+, and D2H+. Semi-classical results differ from the classical Langevin calculations by an order of magnitude (Moyano et al. 2004). To resolve this discrepancy, we have carried out laboratory measurements for these three reactions. Absolute cross sections were measured using a dual-source, merged fast-beams apparatus for relative collision energies between ~10 meV to ~10 eV (Hillenbrand et al. 2019). A semi-empirical model was developed incorporating high level quantum mechanical ab initio calculations for the zero-point-energy-corrected potential energy barrier in order to generate thermal rate coefficients for astrochemical models. Based on our studies, we find that these three reactions proceed too slowly at prestellar core temperatures to play a significant role in the deuteration of H $${ + \over 3}$$ isotopologues.


2016 ◽  
Vol 18 (32) ◽  
pp. 22509-22515 ◽  
Author(s):  
Hongwei Song ◽  
Anyang Li ◽  
Hua Guo ◽  
Yuntao Xu ◽  
Bo Xiong ◽  
...  

A combined experimental–theoretical study of the rovibrationally state-selected ion–molecule reactions H2O+(X2B1; v1+v2+v3+; NKa+Kc++) + H2 (D2) → H3O+ (H2DO+) + H (D), where (v1+v2+v3+) = (000), (020), and (100) and NKa+Kc++ = 000, 111, and 211.


Open Physics ◽  
2011 ◽  
Vol 9 (5) ◽  
Author(s):  
Tianyun Chen ◽  
Ningjiu Zhao ◽  
Weiping Zhang ◽  
Xinqiang Wang

AbstractQuasiclassical trajectory method for the title reaction He +H2+ → HeH+ + H was carried out on the potential energy surface which was revised by Aquilanti et al. [Chem. Phys. Lett. 469, 26 (2009)]. The initial vibrational quantum number of reactant was set as v=1, v=2 and v=3. Stereodynamics information of the reaction was obtained, such as the distributions of product angular momentum P(θ r), P(ϕ r),p(ϕ r, θ r) and the two commonly used polarization-dependent differential cross sections (PDDCSs) (2π/σ)(dσ 00/dω t) and (2π/σ)(dσ 20/dω t), to get the alignment and orientation of product molecules. The results show that the influence of both the collision energy and vibrational quantum number (v) to the reaction are highly sensitive.


2010 ◽  
Vol 88 (12) ◽  
pp. 899-904 ◽  
Author(s):  
Juanjuan Lv ◽  
Xinguo Liu ◽  
Jingjuan Liang ◽  
Haizhu Sun

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.


2012 ◽  
Vol 11 (01) ◽  
pp. 87-97 ◽  
Author(s):  
YINGYING CHEN ◽  
MEIYU ZHAO

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.


2009 ◽  
Vol 08 (supp01) ◽  
pp. 1045-1051
Author(s):  
YAN QI ◽  
ZHI-XIN DUAN

Using quasi-classical trajectory (QCT) method, the vector correlation between products and reagents for the exothermic reaction Ba + CH3I → BaI + CH3 has been studied on the extended Lond–Eyring–Polanyi–Sato (LEPS) potential energy surface (PES) at three collision energies of 1.6, 3.3, and 5.6 kcal/mol. The P(θr) distribution of the products describing the k-j' correlation and the dihedral angle distribution P(ϕr) describing k-k'-j' correlation are calculated in center-of-mass (CM) frame. Four polarization dependent generalized differential cross-sections (2π/σ)(dσ00/dωt), (2π/σ)(dσ20/dωt), (2π/σ)(dσ22+/dωt), and (2π/σ)(dσ21-/dωt) have also been presented in the CM frame as well. The results indicate that the product rotational angular momentum j' is not only aligned, but also oriented along the direction perpendicular to the scattering plane. In addition, the alignment and the orientation of the BaI product rotational angular momentum depend very sensitively on the collision energy.


2010 ◽  
Vol 09 (01) ◽  
pp. 327-339 ◽  
Author(s):  
YUFANG LIU ◽  
XIAOHU HE ◽  
YALI GAO ◽  
JINFENG SUN

The product angular momentum polarization of the Cl + C2D6 → DCl + C2D5 reaction is calculated via the quasiclassical trajectory (QCT) method at the collision energy of 0.25 eV. A new London–Eyring–Polanyi–Sato (LEPS) potential energy surface (PES) is used in this reaction. There is a "late" barrier and a "deep" well on this new LEPS PES. The four polarization-dependent "generalized" differential cross sections (PDDCSs) are presented in the center-of-mass frame. In the meantime, the distributions of P(ϕr), P(θr), and P(θr, ϕr) are calculated. The calculations are in good agreement with the experimental data. In addition, the rotational alignment factors [Formula: see text], [Formula: see text], and [Formula: see text] in the stationary-target frame (STF) are also calculated.


2011 ◽  
Vol 10 (01) ◽  
pp. 1-7 ◽  
Author(s):  
QIANG WEI ◽  
YING KE XIE ◽  
WEN LIN FENG

Quasi-classical trajectory (QCT) method is used to study the stereo-dynamics of the title reaction on the ground 1 1A′ potential energy surface (PES). Differential cross-sections (DCSs) and alignments of the product rotational angular momentum for the reaction are reported. The influence of collision energy on the product vector properties is also studied in the present work. The distribution of angle between k and j′, P(θr), the distribution of dihedral angle denoting k-k′-j′ correlation, P(ϕr) ⋅ (2π/σ)( d σ00/ d ωt), (2π/σ)( d σ20/ d ωt), (2π/σ)( d σ22+/ d ωt) and (2π/σ)(dσ21-/dωt) have been calculated in the center of mass frame, respectively.


Sign in / Sign up

Export Citation Format

Share Document