Quantum Dynamical Rate Constant for the H + O₃ Reaction Using a Six-Dimensional Double Many-Body Expansion Potential Energy Surface

Abstract

We present a quantum mechanical, three-dimensional, infinite-orden-sudden-approximation study of the H + O 3 atmospheric reaction using a recently reported double many-body expansion potential energy surface for ground-state HO 3 . The results are compared with existing experimental data and previously reported quasiclassical trajectory calculations which employed the same interaction potential. Agreement with the recommended experimental data is moderate, but encouraging when compared with the data of Clyne and Monkhouse, which extends over the range of temperatures 300 e T/K e 650, and with the recent measurement of Greenblatt and Wiesenfeld for T ) 300 K. In comparison with the classical trajectory results, the agreement is also moderate, the differences being attributed to both methodological approximations in the quantum formalism and the problem of zero-point energy leakage in classical dynamics.

Quantum scattering study of electronic Coriolis and nonadiabatic coupling effects in O(1D)+H2→OH+H

“…where H 11 is the ⌺ surface, H 22 Note that the diagonal terms in this expression involve the average of H 22 and H 33 , so in the limit that H 13 is small, it is the average potential that governs the ⌸ state dynamics, and the difference potential that provides the coupling. Of course the adiabatic states obtained from diagonalizing Eqs.…”

“…Instead, it may be feasible to concentrate on the coupled dynamics that takes place while the reactants approach, since this is where the reactive bottleneck is located, and to use negative imaginary potentials ͑nips͒ to absorb the reactive flux that goes to products. The nips approach to reactive scattering has been used in the past [21][22][23][24][25] for reactions that involve a single potential energy surface or even for multiple surfaces where Coriolis effects were neglected. Another simplifying feature of reactions that are dominated by capture dynamics is that the evolution of the vibrational motions can often be approximated as adiabatic, i.e., following the changing shape of the potential as the reactant bond is distorted and eventually broken.…”

Quasiclassical Trajectory Study of the Environmental Reaction O + HO2 → OH + O2

“…In this work we have used the six-dimensional (6D ) DMBE potential energy surface 10 for ground-state HO 3 , which has been previously employed 11,12 to study reaction 4 with good results. Since it has been described in detail elsewhere, 10 we focus here on its main topographical features which are of relevance for the title reaction.…”

Hyperspherical harmonics for tetraatomic systems

“…Time-dependent and timeindependent wave-packet methods have been used for the total angular momentum Jϭ0 partial wave of such reactions, [7][8][9][10][11][12][13][14][15] but for JϾ0 only approximate techniques have been used. No completely converged state-to-state differential cross sections have yet been obtained by these methods.…”