Spin-orbit effect in the energy pooling reaction O2(aΔ1)+O2(aΔ1)→O2(bΣ1)+O2(XΣ3)

O2(b1Σg+) Quenching by O2, CO2, H2O, and N2 at Temperatures of 300-800 K

Rate constants for the removal of O₂(b¹Σ_g⁺) by collisions with O₂, N₂, CO₂, and H₂O have been determined over the temperature range from 297 to 800 K. O₂(b¹Σ_g⁺) was excited by pulses from a tunable dye laser, and the deactivation kinetics were followed by observing the temporal behavior of the b¹Σ_g⁺-X³Σ_g^- fluorescence. The removal rate constants for CO₂, N₂, and H₂O were not strongly dependent on temperature and could be represented by the expressions k_CO2 = (1.18 ± 0.05) × 10^-17 × T^1.5 × exp[Formula: see text], k_N2 = (8 ± 0.3) × 10^-20 × T^1.5 × exp[Formula: see text], and k_H2O = (1.27 ± 0.08) × 10^-16 × T^1.5 × exp[Formula: see text] cm³ molecule^-1 s^-1. Rate constants for O₂(b¹Σ_g⁺) removal by O₂(X), being orders of magnitude lower, demonstrated a sharp increase with temperature, represented by the fitted expression k_O2 = (7.4 ± 0.8) × 10^-17 × T^0.5 × exp[Formula: see text] cm³ molecule^-1 s^-1. All of the rate constants measured at room temperature were found to be in good agreement with previously reported values.

Quantum wave packet and quasiclassical trajectory studies of the reaction H(2S) + CH(X2 Π; v = 0, j = 1) → C(1D) + H2 (X1 Σg+): Coriolis coupling effects and stereodynamics

The quantum mechanics (QM) and quasiclassical trajectory (QCT) calculations have been carried out for the title reaction with the ground minimal allowed rotational state of CH (j = 1) on the 1 (1)A' potential energy surface. For the reaction probability at total angular momentum J = 0, a similar trend of the QM and QCT calculations is observed, and the QM results are larger than the latter almost in the whole considered energy range (0.1-1.5 eV). The QCT integral cross sections are larger than the QM results with centrifugal sudden approximation, while smaller than those from QM method including Coriolis coupling for collision energies bigger than 0.25 eV. The quantum wave-packet computations show that the Coriolis coupling effects get more and more pronounced with increasing of J. In addition to the scalar properties, the stereodynamical properties, such as the average rotational alignment factor <P2 (j'•k)>, the angular distributions P(θr ), P(ϕr ), P(θr ,ϕr ), and the polarization-dependent generalized differential cross sections have been explored in detail by QCT approach.

Attosecond-resolution quantum dynamics calculations for atoms and molecules in strong laser fields

A parallel quantum electron and nuclei wave packet computer code, LZH-DICP, has been developed to study laser-atom-molecule interaction in the nonperturbative regime with attosecond resolution. The nonlinear phenomena occurring in that regime can be studied with the code in a rigorous way by numerically solving the time-dependent Schrödinger equation of electrons and nuclei. Time propagation of the wave functions is performed using a split-operator approach, and based on a sine discrete variable representation. Photoelectron spectra for hydrogen and kinetic-energy spectra for molecular hydrogen ion in linearly polarized laser fields are calculated using a flux operator scheme, which testifies to the validity and the high efficiency of LZH-DICP.