Reagent vibrational, rotational and isotopic effects on stereodynamics of the H + OCl → OH + Cl reaction

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.

SEVEN-DIMENSIONAL QUANTUM DYNAMICS STUDY OF THE H2 + NH2 → H + NH3 REACTION ON AN INTERPOLATED POTENTIAL ENERGY SURFACE

Initial-state-selected time-dependent wave packet dynamics studies have been performed for the H 2 + NH 2 → H + NH 3 reaction with a seven-dimensional model on a new interpolated ab initio potential energy surface (PES). The PES is constructed using modified Shepard interpolation Scheme and contains 1967 data points with ab initio calculations carried out on UCCSD(T)/aug-cc-pVTZ level. In the seven-dimensional model, NH 2 group keeps C2v symmetry and two NH bonds are fixed at their equilibrium values. The total reaction probabilities are calculated when (1) the two reactants are initially at their ground states; (2) NH 2 bending mode is excited, and (3) H 2 is on its first vibrational excited state. The integral cross sections are also reported for these initial states with centrifugal-sudden approximation. Thermal rate constants are calculated for the temperature range of 200–2000 K and compared with the previous calculated values and available experimental data. Good agreements between theory and experiments for the rate constants at intermediate temperature are achieved on this PES.

THE INVESTIGATION OF NON-OSCILLATING STRUCTURE OF THE PHOTODETACHMENT CROSS SECTION OF MOLECULAR ANION USING TRADITIONAL THEORETICAL IMAGING METHOD

Using traditional theoretical imaging method, we predict invisible oscillations in the photodetachment cross section of [Formula: see text] near a thin soft surface. A laser which is polarized parallel to the surface is used to knock off electron from [Formula: see text]. Analytical expressions are derived for detached electron flux and photodetachment cross section. The results depend on the inter ion surface distance and separation of the atomic centers of the molecular anion. It is found that the surface strongly affects the detached electron flux and the photodetachment cross section. Unlike the detached electron flux the cross section displays non-oscillating structure. The non-oscillating structure is attributed to the parallel orientation of the laser polarization direction with the thin elastic surface.

THEORETICAL STUDY OF THE STEREODYNAMICS OF THE N(4S) + D2 → ND + D REACTION ON THE DMBE SURFACE

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.