Quantum and Quasiclassical Dynamics of the ${\rm\bf C}(\bf ^3P)$ + ${\rm\bf H_2}(\bf ^1\Sigma_g^+)$ $\rightarrow$ ${\rm\bf H}(\bf ^2S)$ + ${\rm\bf CH}(\bf ^2\Pi)$ reaction: Coriolis Coupling Effects and Stereodynamics

The dynamics of ${\rm\bf C}$ + ${\rm\bf H_2}$ $\rightarrow$ ${\rm\bf H}$ + ${\rm\bf CH}$ reaction is theoretically studied using the quasiclassical trajectory and quantum mechanical wave packet methods. The analysis of reaction probabilities, integral cross sections and rate coefficients reveal the essential coriolis coupling effects in the quantum mechanical wave packet calculations. The calculated polarization-dependent differential cross section, P($\theta_r$) and P($\phi_r$) show that the $\bf j'$ of product rotational angular momentum is not only aligned along the y-axis and the direction of the vector $\bf x+z$, but also strongly oriented along the positive y-axis.

Microscopic description of α-decay as super-asymmetric fission

The fine structure of α-decay is treated with fission-like models. The single particle levels are calculated along a least action path connecting the ground state of the parent nucleus and the configuration of two spherical tangent nuclei. The probabilities to find different seniority-1 configurations are obtaining by solving the time-dependent pairing equations generalized by including the Landau-Zener effect and the Coriolis coupling. The theoretical results for the α-decay of 211Po and 211Bi are compared with experimental data showing a good agreement.

A semiclassical approach to the torsional tunneling splitting patterns in G6(EM), G12, G18, and G36(EM) molecules

A semiclassical method to predict the torsional splitting patterns in internally rotating molecules of G6(EM), G12, G18, and G36(EM) symmetries is described. To this purpose use is made of rotating axis systems denoted “Corioless”, in which the contribution to the torsional angular momentum from specific vibrational motions of the molecule, or part of it, vanishes. It is confirmed that the actual torsional splitting patterns in degenerate or perpendicular vibrational states can be predicted analytically and are determined by torsional Coriolis coupling. Rules stating the conditions required to generate limit splitting patterns (regular and inverted) are formulated in a quite general way and derived for the first time in the case of G18 molecules.

On neglecting Coriolis and related couplings in first-principles rovibrational spectroscopy: considerations of symmetry, accuracy, and simplicity

The rotation-vibration (Coriolis) coupling contribution to variationally computed rovibrational energy levels is investigated, employing triatomic AB$${}_{2}$$2 molecules as models. In particular, calculations are performed for H$${}_{2}$$2$${}^{16}$$16O, across a range of vibrational and rotational excitations, both with and without the Coriolis contribution. A variety of different embedding choices are considered, together with a hierarchy of increasingly severe approximations culminating in a generalized version of the so-called “centrifugal sudden” method. Several surprising and remarkable conclusions are found, including that the Eckart embedding is not the best embedding choice.

Quantum wave-packet studies on ion–molecule reaction with and without Coriolis-coupling effect

The time-dependent quantum scattering calculation with Chebyshev wave packet propagation scheme has been carried out based on an accurate electronic potential energy surface of H2O+(X4A″). Due to the influence of the deep potential well, the reaction probability of [Formula: see text] shows resonance structures regardless of the Coriolis-coupling (CC) effect or centrifugal sudden (CS) approximation. In the range of collision energy 0.0–1.0 eV, the integral cross section obtained by the CS approximation calculation is smaller than that by the CC calculation, which indicates that the CC effect plays a significant role in the title reaction.