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1.
The reactive collision process H(+) + D(2)(ν = 0, j = 0) → HD + D(+) is theoretically analyzed for collision energies ranging from threshold up to 1.3 eV. It is assumed that the reaction takes place via formation of a collision complex. In calculations, a statistical theory is used, based on a mean isotropic potential deduced from a full potential energy surface. Calculated integral cross sections, opacity functions, and rotational distributions of the HD products are compared with recent statistical and quantum mechanical calculations performed using a full potential energy surface. Satisfactory agreement between the results obtained using the two statistical methods is found, both of which however overestimate the existing quantum mechanical predictions. The effects due to the presence of identical particles are also discussed. 相似文献
2.
Kinetics and Catalysis - The rate constants of the interactions of chromium atoms with molecular oxygen through recombination Cr + O2 + M → CrO2 + M (I) and exchange Cr + O2 → CrO + O... 相似文献
3.
Qiang Wei Ying Ke Xie Feng Zhang 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2011,85(8):1376-1379
The stereodynamics of the O + HCl → ClO + H reaction are investigated by quasi-classical trajectory (QCT) method. The calculations
are carried out on the ground 1 1
A′ potential energy surface (PES). The orientation and alignments of the product rotational angular momentum for the title
reaction are reported. The influence of collision energy on the product vector properties is also studied in the present work.
Four (2π/σ)(dσ00/dω
t
), (2π/σ)(dσ20/dω
t
), (2π/σ)(dσ22+/dω
t
), and (2π / σ)(dσ21−/dω
t
), and have been calculated in the center of mass frame. 相似文献
4.
Quasi-classical trajectory (QCT) calculations are employed for the reaction F + HO(0,0)→HF + O based on the adiabatic potential energy surface (PES) of the ground 3A″triplet state. The average rotational alignment factor P2(j′·k) as a function of collision energy and the four polarization dependent generalized differential cross sections have been calculated in the center-of-mass (CM) frame, separately. The distribution P(θr) of the angle between k and j′, the distribution P(θr) of dihedral angle denoting k-k′-j′ correlation, and the angular distribution P(θr, Φr) of product rotational vectors in the form of polar plots are calculated as well. The effect of Heavy-Light-Heavy (HLH) mass combination and atom F's relatively strong absorbability to charges on the alignment and the orientation of product molecule HF rotational angular momentum vectors j′ is revealed. 相似文献
5.
For the Li + I2 →Li+ + I2- system, theoretical study has been performed on the QCISD(T) level by using the ab initio method. The collision complex in ion-pair formation process was found and optimized. These results show that the crossed molecule beam (CMB) experimental phenomenon is verified and the detailed geometry is given for the first time. A mechanism for ion-pair formation was proposed in detail. The position where the collision complex occurs affects the reaction path. Specifically, the process has threshold when the collision complex appeared before the crossing point between the covalent and ionic state potential energy surfaces. On the contrary, the process has no threshold after the crossing point. Theoretically, the title system belongs to the former case. 相似文献
6.
《Fluid Phase Equilibria》2004,224(2):251-256
In this work, experimental liquid–liquid equilibria (LLE) of the limonene + ethanol + water system are presented. The LLE of this system has been measured at 293.15, 303.15, 313.15 and 323.15 K. The equilibrium data presented are correlated using NRTL and UNIQUAC equations. Finally, the reliability of these models is tested by comparison with experimental results. 相似文献
7.
First accurate quantum mechanical scattering calculations have been carried out for the S((3)P)+OH(X?(2)Π)→SO(X?(3)Σ(-))+H((2)S) reaction using a recent ab initio potential energy surface for the ground electronic state, X?(2)A("), of HSO. Total and state-to-state reaction probabilities for a total angular momentum J=0 have been determined for collision energies up to 0.5 eV. A rate constant has been calculated by means of the J-shifting approach in the 10-400 K temperature range. Vibrational and rotational product distributions show no specific behavior and are consistent with a mixture of direct and indirect reaction mechanisms. 相似文献
8.
Greaves SJ Rose RA Abou-Chahine F Glowacki DR Troya D Orr-Ewing AJ 《Physical chemistry chemical physics : PCCP》2011,13(23):11438-11445
We present an on-the-fly classical trajectory study of the Cl + CH(4)→ HCl + CH(3) reaction using a specific reaction parameter (SRP) AM1 Hamiltonian that was previously optimized for the Cl + ethane reaction [S. J. Greaves et al., J. Phys Chem A, 2008, 112, 9387]. The SRP-AM1 Hamiltonian is shown to be a good model for the potential energy surface of the title reaction. Calculated differential cross sections, obtained from trajectories propagated with the SRP-AM1 Hamiltonian compare favourably with experimental results for this system. Analysis of the vibrational modes of the methyl radical shows different scattering distributions for ground and vibrationally excited products. 相似文献
9.
A J C Varandas 《Chemphyschem》2005,6(3):453-465
Vibrationally excited O2, OH, and HO2 species have been suggested (J. Phys. Chem. A 2004, 108, 758) to provide clues for explaining the "ozone deficit problem" and "HOx dilemma" in the middle atmosphere under conditions of local thermodynamic disequilibrium (LTD), but the question arises of how much LTD will affect the title ozone sink reactions. Besides providing novel kinetic results, it is shown that LTD tends to disfavor ozone depletion relative to traditional atmospheric modeling under Boltzmann equilibration, which is partly due to competition between the various reactive channels. The calculations also suggest that the title LTD processes can be important sources of highly vibrationally excited O2 in the middle atmosphere. Moreover, LTD is shown to offer an explanation for the fact that some down revision of the O + HO2 rate constant, or the ratio of the O + HO2 to O + OH rate constants, is required to improve agreement between the predictions of traditional modeling and observation. This, in turn, provides significant evidence supporting LTD at such altitudes. 相似文献
10.
11.
12.
Russian Journal of Applied Chemistry - The process of hydrolysis in the Al3+-Cd2+-NO 3 ? -H2O and Al3+-Hg2+-NO 3 ? -H2O systems is studie by the methods of pH-metric titration and... 相似文献
13.
《Chemical physics letters》1985,122(5):489-492
The rate constant for the bimolecular reaction CO + N2O → CO2 + N2 was determined by comparison of calculated infrared emission profiles of CO2 with those observed in shock-tube experiments in the temperature range 1350–2100 K for CO-N2O-He-Ar mixtures. The rate constant was found to be k1 = 3.2 × 1011exp(−85 kJ/RT) cm3 mol−1 s−1. 相似文献
14.
《Chemical physics letters》1986,132(1):44-49
The difference in energy between the singlet and triplet states of NaK dissociating to Na(3s) and K(4s) is found from experimental data and from pseudopotential calculations. The contributions of various one- and two-electron integrals are evaluated, illustrating the present ambiguity over the exchange integral and the exchange interaction terms. 相似文献
15.
ZHANG Xinzhuang ZHEN Zhen & LIU Xinhou Technical Institute of Physics Chemistry of Chinese Academy of Sciences Beijing China 《中国科学B辑(英文版)》2005,48(4)
HNCO is a convenient photolytic source of NCO and NH radicals for laboratory kinetics studies of elementary reaction[1] and plays an important role in the combustion and atmosphere chemistry. It can re- move deleterious compounds rapidly from exhausted ga… 相似文献
16.
《Chemical physics》1987,114(1):1-7
The first six 2Σ+g adiabatic potential energy curves of He+2 are calculated with the MRD CI method employing configuration selection (T = 10 μ hartree) and perturbative energy corrections and using two basis sets differing in the number of diffuse functions. The non-adiabatic matrix elements at the numerous avoided crossings are also calculated and approximate diabatic curves are constructed. Various aspects of the results are discussed. 相似文献
17.
《Fluid Phase Equilibria》2004,216(1):13-20
Liquid–liquid equilibria of the ternary system water + tetradecane + 2-butyloxyethanol in the temperature range from 298.15 to 338.15 K were investigated at atmospheric pressure. The experimental data correlated well with the UNIQUAC model. For the system with a three-liquid-phase-coexisting region, all the six UNIQUAC interaction parameters can be determined numerically by minimizing the deviation of the compositions of three coexisting liquid phases only. 相似文献
18.
《Chemical physics》1987,114(2):241-249
The three-dimensional potential energy surface for the reaction of Ca and HF has been obtained from a two-configuration direct minimization method using an extended GTO basis set. Features of the surface were examined by fitting calculated values using cubic splines. The height of the barrier to reaction was found to be quite insensitive to the direction of the impinging Ca atom for a wide range of angles of approach. The transition state occurs in the exit channel at an angle of approach of 77°, 33.6 kcal/mole (or 14.8 kcal/mole if the correlation energy error is considered) above the reactants asymptote. A further analysis of the basis set superposition error and the correlation energy error is presented, these results modify the dynamical properties of the system and give a criterion to test the validity of the previously reported two-configuration PES for BeFH and MgFH systems. 相似文献
19.
《Chemical physics letters》1985,116(5):439-442
Quantum-mechanical transition probabilities are presented for the molecule HCl(υi) reacting with a solid surface S, i.e. HCl(υi)+S → HS+Cl; υi = 0,…,4. The calculations were done for a fixed parallel approach (γ = π/2) of the molecule. Results are shown as a function of total energy Etot for the energy range 1.95 ⩽ Etot ⩽ 3.3 eV. 相似文献
20.
《Radiation Physics and Chemistry》2009,78(3):191-194
In a recent paper (Radiation Physics and Chemistry, 2005, vol. 74, pp. 210) it was suggested that the anomalous increase of molecular hydrogen radiolysis yields observed in high-temperature water is explained by a high activation energy for the reaction H+H2O→H2+OH. In this comment we present thermodynamic arguments to demonstrate that this reaction cannot be as fast as suggested. A best estimate for the rate constant is 2.2×103 M−1 s−1 at 300 °C. Central to this argument is an estimate of the OH radical hydration free energy vs. temperature, ΔGhyd(OH)=0.0278t−18.4 kJ/mole (t in °C, equidensity standard states), which is based on analogy with the hydration free energy of water and of hydrogen peroxide. 相似文献