Full six-dimensional nonadiabatic quantum dynamics calculation for the energy pooling reaction O2(aΔ1)+O2(aΔ1)→O2(bΣ1)+O2(XΣ3)

Abstract

Six new potential energy surfaces of four singlet states and two triplet states for the title oxygen molecule reaction along with the spin-orbit coupling among them have been constructed from the complete active space second-order perturbation theory with a 6-311+G(d) basis. Accurate integral cross sections are calculated with a full six-dimensional nonadiabatic time-dependent quantum wave packet method. The thermal rate constant based on the integral cross sections agrees well with the result of the experimental measurements, and the intersystem crossing effects are also discussed in this electronic energy-transfer process.

The validities of centrifugal sudden approximations in chemical reaction dynamics

“…It is of great significance to carry out studies on the validities of the CS approximations in tetratomic and polyatomic systems, possibly combined with a full exploration of the PESs of reaction systems . To date, some efforts have been devoted to investigate the accuracy of the CS approximation in different tetraatomic and polyatomic systems .…”

“…There has a growing interest in accurately computing the nonadiabatic dynamical quantities of benchmark chemical reactions on several potential energy surfaces (PESs) and in computing the corresponding quantities of tetraatomic and polyatomic chemical reactions. This research interest is motivated by the successful development of the nonadiabatic dynamical methods, in particular of quantum mechanical methods, , and by the great advances in quantum mechanical methods for tetraatomic and polyatomic reactions . However, the inclusion of multiple electronic states in the nonadiabatic treatment and the increase in atom numbers in a reactive system caused extremely difficulty to the quantum scattering calculations due to the rapid increase of basis functions, and a careful examination of CS approximations is essentially helpful in finding a balance between abating such computational difficulty and computational accuracy.…”

“…To describe the nonadiabatic dynamical features of chemical reactions, Han and coworkers have recently developed the nonadiabatic time‐dependent wave packet approach with a computational scale of no more than N 2 log N . Here, N denotes the number of basis functions used in the nonadiabatic scattering calculations.…”

Quenching of OH(A2Σ+) by H2 through Conical Intersections: Highly Excited Products in Nonreactive Channel

“…The nonadiabatic quantum scattering approach for this system is the same as that in the previous work on the O 2 +O 2 reaction . The Hamiltonian for the diatom−diatom Hamiltonian reaction in the Jacobi coordinates can be written as H = − ℏ 2 2 normalμ ∂ 2 ∂ R 2 + false( Ĵ − Ĵ 12 false) 2 2 normalμ R 2 + h 1 false( r 1 false) + h 2 false( r 2 false) + j ̂ 1 2 2 normalμ 1 r 1 2 + j ̂ 2 2 2 normalμ 2 r 2 2 + V false( true italicr ⃗ 1 , true italicr ⃗ 2 , true itali...…”

Memorial Viewpoint for Keli Han

“…Prof. Han was also one of the first people to study nonadiabatic quantum dynamics on neural network potential energy surfaces using GPU-accelerated computational methods. He and his colleagues carried out six-dimensional nonadiabatic quantum scattering calculations for the first time in 2008 . They introduced a new split-operator method and a transformation procedure for both adiabatic and nonadiabatic state-to-state quantum dynamics studies in 2013, which accelerated computation by 2 orders of magnitude.…”