共查询到19条相似文献,搜索用时 562 毫秒
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基于2003年Alfredo Aguado 等人构造的新势能面(Aguado和Paniagua. J. Chem. Phys., Vol. 119, No. 19, 2003), 本文结合振动激发和碰撞能两个因素,采用准经典轨线的方法对反应Li+HF(v=0–3) 的k-j' 两矢量相关和k-k'-j'三矢量相关的分布函数及极化微分反应截面进行了详细的立体动力学研究. 结果表明, 描述三原子分子反应的k-j'两矢量相关联的函数P(θr)分布不受振动激发影响, 而碰撞能则对其影响较大. 描述 k-k'-j'三矢量相关的函数P(φr)分布和极化微分反应截面对振动激发较敏感, 同时我们发现碰撞能对P(φr)分布和极化微分反应截面也有较大影响.
关键词:
矢量相关
立体动力学
准经典轨线方法
极化微分反应截面 相似文献
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基于翟红生和韩克利给出的势能面[Zhai H S, Han K L 2011 J. Chem. Phys. 135 104314], 运用准经典轨线方法对H+NH及其同位素取代反应的立体动力学性质进行了理论研究. 分别计算并讨论了碰撞能Ec=8和16 kcal/mol时反应的极化微分反应截面、两矢量k-j'相关分布函数P(θr)、 三矢量 k- k'- j'相关分布函数P(φr)、空间分布函数P(θr, φr). 结果表明, 对于上述的两个碰撞能, 由于同位素取代反应中质量因子的不同, 同位素效应对H+NH反应的立体动力学性质的影响很明显. 相似文献
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李兴 《原子与分子物理学报》2012,29(2):241-246
利用从头计算的对称性为1A′的势能面,用准经典轨线(QCT)方法在不同的碰撞能下研究了反应H+CH→H2+C(1D)的产物和反应物的矢量相关性质.在质心系下计算了四个极化微分反应截面.计算并讨论了描述k和j′夹角分布关系的P(θr)和描述k-k′-j′三者的二面角分布关系的P((?)r).计算结果表明势能面上的深势阱和不同的碰撞能对产物分子H2有重要影响. 相似文献
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采用准经典轨线方法,基于半经验的London-Eyring-Polanyi-Sato势能面,研究了碰撞能对碰撞反应Sr+CH3I→SrI+CH3的立体动力学性质的影响.结果表明,反应物的初始碰撞能对产物转动角动量矢量的取向和定向程度都有重大影响. 相似文献
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采用准经典轨线方法研究碰撞能为0.23 eV时,反应物分子NO在不同初始振动态(v=0~3)下发生在两个电子态(2A″和2A')势能面上反应C(3P)+NO(X2Π)→CO(X1Σ+)+N(2D)的立体动力学性质。计算反应产物的转动角动量矢量分布(P(θr)和P(φr))以及微分散射截面(P00(ωt),P20(ωt))。结果表明:反应物的振动激发对发生在2A'势能面上的反应立体动力学性质影响显著,而对发生在2A″势能面上的反应立体动力学性质影响较小,这可能与两个势能面的构型有关。在两个电子态势能面上发生的反应均受内平面反应机理支配。 相似文献
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在Peterson的高精度从头计算势能面上,运用准经典轨线方法讨论了反应物分子初始振动激发对O+HCl→OH+Cl反应的立体动力学性质的影响.反映两矢量k-j′相关的P(θr)函数的分布说明产物的转动角动量j′在垂直于反应物相对速度矢量k的方向上的排列取向程度随着初始反应物振动量子数的增加而增加;反映三矢量k-k′-j′相关的极角分布函数P(r)显示产物的转动角动量有比较弱的定向效应,且随着初始振动量子数的增加,这种弱的定向效应由沿Y轴负向变为沿Y轴正向.说明反应物分子的初始振动激发有利于增强产物分子的转动排列取向效应,但对产物分子P(r)分布的影响则不明显. 相似文献
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Effect of ro-vibrational excitation of NeH~+ on the stereodynamics for the reactions H+NeH~+(v=1-3,j=1,3,5) →H_2~++Ne 下载免费PDF全文
The stereodynamics of the abstraction reaction H + NeH+(v = 1-3,j = 1,3,5) → H2+ + Ne is studied theoretically with a quasi-classical trajectory method on a new ab initio potential energy surface [ S J,Zhang P Y,Han K L and He G Z 2012 J.Chem.Phys.132 014303].The effects of vibrational and rotational excitation of reagent molecules on the polarization of the product are investigated.The reaction cross sections,the distributions of P(θr),P(φr),and polarizationdependent differential cross sections(PDDCSs) are calculated.The obtained cross sections indicate that the title reaction is a typical barrierless atom(ion)-ion(molecule) reaction.The initial vibrational excitation and rotational excitation of reagent molecules have distinctly different influences on stereodynamics of the title reaction,and the possible reasons for the differences are presented. 相似文献
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P. PALMIERI C. PUZZARINI V. AQUILANTI G. CAPECCHI S. CAVALLI D. DE FAZIO 《Molecular physics》2013,111(21):1835-1849
The reaction He + H+ 2(v,j = 0) → HeH+(v′ = 0, j′) for v = 0, 1,2 and 3 and for scattering energies near the threshold (0.95–1.15 eV) has been studied by calculating ab initio points at MRCI level and ‘exact’ integral quantum reactive cross-sections. More than 1400 nuclear geometries have been chosen to cover the most important regions for the dynamics, an extended set of points being taken directly on a hyperspherical coordinate grid. A many-body expansion with a large number of terms permits an accurate analytical representation of the potential energy surface with a root-mean-square deviation <12meV. The hyperquantization algorithm has been extended to obtain quantum mechanical integral cross-sections which are compared with previous calculations and with experimental results. 相似文献
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Influence of rotational excitation and collision energy on the stereo dynamics of the reaction: N(4S)+H2 (v = 0, j = 0, 2, 5, 10) →NH(X3∑-)+H 下载免费PDF全文
The N+H2 reaction has attracted a great deal of attention from both the experimental and the theoretical community, and most of the attention has been paid to the first excited state N(2D) atoms in collisions with hydrogen molecules and the scalar properties of the reaction. In this paper, we study the stereo dynamical properties and calculate the reaction cross sections of the N(4S) + H2 (v=0, j=0, 2, 5, 10) → NH(X3Σ-) + H using the quasi-classical trajectory (QCT) method on an accurate NH2 potential energy surface (PES) reported by Poveda and Varandas [Poveda L A and Varandas A J C 2005 Phys. Chem. Chem. Phys. 7 2867], in a collision energy range of 25 kcal·mol-1-140 kcal·mol-1. Results indicate that the reactant rotational excitation and initial collision energy both have a considerable influence on the distributions of the k-j′ correlation, the k-k′-j′ correlation and k-k′ correlation. The differential cross section is found to be sensitive to collision energy. 相似文献
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A new Penning-electron-Penning-ion coincidence method is described. It is applied to the study of the thermal reaction of He(23S) with H2. The main results reported are separate electron energy spectra that are coincident with the three different ions formed: HeH2+, HeH+ and H2+. Based on these results it is shown that the Penning reaction of the He(23S)/H 2 system proceeds in two well-separated steps: (i) ionization at distances R (HeH2) ? 6a0 in which H2+ (v) is formed in different vibrational states; and (ii) reactive collision of H2+ (v) with He. For the second step the variation of the branching ratios with vibrational quantum numbers v = 0 to v = 10 is derived, and it is shown that these branching ratios may be regarded as relative vibrational-energy-dependent cross-sections for the collision of H2+ (v) with He at an average relative kinetic energy of ~20 meV. 相似文献
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Yasuaki Mizuno Masataka Hasegawa Yasufumi Susuki Kenji Kimura Michi-Hiko Mannami 《辐射效应与固体损伤》2013,168(1-3):131-137
Abstract Convoy electrons produced at glancing angle scattering of MeV HeH+ ions from an atomically clean (001) surface of SnTe crystal are observed. Energy spectrum of the convoy electrons shows a peak broader than that at scattering of atomic projectiles and the most probable energy of convoy electrons at HeH+ scattering is larger than those at scattering of isotachic He ions. This acceleration of convoy electrons is qualitatively explained by the force due to surface wake induced by Coulomb exploding fragment He2+ and H+. 相似文献
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In this paper, we are interested in the asymptotic properties for the largest eigenvalue of the Hermitian random matrix ensemble,
called the Generalized Cauchy ensemble GCyE, whose eigenvalues PDF is given by
const·?1 £ j < k £ N(xj-xk)2?j=1N(1+ixj)-s-N(1-ixj)-[`(s)]-Ndxj,\textrm{const}\cdot\prod_{1\leq j 18.
F. Laue I. Böttcher M. Debowski A. Förster E. Grosse P. Koczoń B. Kohlmeyer M. Mang M. Menzel L. Naumann H. Oeschler F. Pühlhofer E. Schwab P. Senger Y. Shin J. Speer H. Ströbele C. Sturm G. Surówka F. Uhlig A. Wagner W. Waluś 《The European Physical Journal A - Hadrons and Nuclei》2000,9(3):397-410
Production cross-sections of charged pions, kaons and antikaons have been measured in C+C and C+Au collisions at beam energies
of 1.0 and 1.8 AGeV for different polar emission angles. The kaon and antikaon energy spectra can be described by Boltzmann
distributions whereas the pion spectra exhibit an additional enhancement at low energies. The pion multiplicity per participating
nucleon M(π+)/<A
part> is a factor of about 3 smaller in C+Au than in C+C collisions at 1.0 AGeV whereas it differs only little for the C and the
Au target at a beam energy of 1.8 AGeV. The K+ multiplicities per participating nucleon M(K+)/ <A
part> are independent of the target size at 1 AGeV and at 1.8 AGeV. The K- multiplicity per participating nucleon M(K-)/ <A
part> is reduced by a factor of about 2 in C+Au as compared to C+C collisions at 1.8 AGeV. This effect might be caused by the
absorption of antikaons in the heavy target nucleus. Transport model calculations underestimate the K-/K+ ratio for C+C collisions at 1.8 AGeV by a factor of about 4 if in-medium modifications of K-mesons are neglected.
Received: 10 December 1999 / Accepted: 14 November 2000 相似文献
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