Quasi-classical trajectory study of the cross sections of the reactions of D−+H2→H−+HD and H−+D2→D−+HD

Quantum state-to-state study for (H−(D−),HD) collisions on two potential energy surfaces

Revealing the reaction mechanisms of the H⁻/D⁻ + HD reaction – an exact quantum dynamics study on two potential energy surfaces.

Quasi-classical trajectory study of the reaction dynamics of calcium ground state and metastable atoms with CH2Cl2

The dynamics properties of the Ca(1S0,3P) + CH2Cl2 reaction system have been calculated by means of the quasi-classical trajectory method based on the extended London–Eyring–Polanyi–Sato potential energy surface. By the calculations, the vibrational distribution, reaction cross section, rotational alignment, and reaction rate constant are obtained. The peak location of vibrational quantum numbers is at ν = 0 when the collision energy is 2.302 kcal/mol, whether the calcium atom is at the ground state or metastable state. The product vibrational distribution agrees well with the experiment value in Han, K. L.; He, G. Z.; Lou, N. Q. Chem. Phys. Lett. 1991, 178, 528. The cross section thoroughly decreases with the increase of the collision energy. The rotational alignment of the product greatly deviates from –0.5. The reaction rate constant increases with rising temperature.

Time-dependent wave packet quantum scattering and quasi-classical trajectory calculations of the H + FCl(v=0,j=0) → HF + Cl/HCl + F reaction

The dynamics of the title reaction are investigated using both time-dependent wave packet quantum scattering and quasi-classical trajectory (QCT) methods on adiabatic ground 1(2)A' potential energy surface (PES). Compared with the quantum results of reaction probabilities of H + FCl(J=0) → HF + Cl/HCl + F, the QCT method is proven feasible and further employed to produce integral cross sections and rate constants. Significant resonance structures are observed in the reaction probabilities using the quantum method; however, there are some undulations in the calculated QCT integral cross sections for both product channels. A comparison between the quantum mechanical coupled-channel (CC) calculation and centrifugal sudden approximation calculation reveals the very important role of Coriolis coupling effects in the quantum calculation. Comparisons between the calculated thermal rate constants for both reactions and the previous theoretical and experimental results have been done. HCl product formation is favored over the HF product in the reactive system. Finally, the HF products are found to be mainly forward scattering, and the HCl products are mainly backward scattering.

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

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.

Isotopic effects on stereodynamics for the two reactions: H + LiH+(v = 0, j = 0) --> H2 + Li+ and H+ + LiH(v = 0, j = 0) --> H2(+) + Li

The isotopic effects on stereodynamic properties for the title reactions occurring on the two lowest-lying electronic potential energy surfaces (PESs) of LiH(2)(+) are investigated in detail by means of the quasi-classical trajectory (QCT) method at a collision energy of 0.5 eV, using the ab initio potential energy surfaces (PESs) of Martinazzo et al. (J. Chem. Phys., 2003, 119, 11241). The corresponding reactions comprise: (i) H/D/T + LiH(+) --> HH/HD/HT + Li(+) and H + LiH(+)/LiD(+)/LiT(+) --> HH/HD/HT + Li(+); (ii) H(+)/D(+)/T(+) + LiH --> HH(+)/HD(+)/HT(+) + Li and H(+) + LiH/LiD/LiT --> HH(+)/HD(+)/HT(+) + Li. Differential cross sections (DCSs) and alignments of the product rotational angular momentum for all of these reactions are reported. The results illustrate that the reason for the abnormal behavior of the DCSs for the title reactions reported in the previous work is ascribed to the sensitive role of the projectile atomic mass, and indicate that the long-range interactions play a more important role than the mass factor in ion-molecule reactions. The current topic for this special mass combination system shows some new features of the stereodynamics differing from the previous studies for "typical" mass-combination reactions.