Nonadiabatic energy transfer studies of O(1D)+N2(X 1Σg+)→O(3P)+N2(X 1Σg+) by time-dependent wave packet

Three-dimensional time-dependent quantum calculations have been performed on two/three coupled potential surfaces, including the singlet surface 1 (1)A(') and two triplet surfaces 1 (3)A(') and 1 (3)A", for the electronic quenching process of O(D-1)+N-2(X (1)Sigma(g)(+))-->O(P-3)+N-2(X (1)Sigma(g)(+)). An extended split-operator scheme was employed to study this nonadiabatic process. Two types of singlet surface 1 (1)A('), namely, double many body expansion (DMBE2) [Nakamura and Kato, J. Chem. Phys. 110, 9937 (1999)] and ZPM2 [Zahr, Preston, and Miller, J. Chem. Phys. 62, 1127 (1975)] were used in the calculations, along with spin-orbit couplings of Nakamura-Kato and with a constant value of 80 cm(-1). All the calculated probabilities are resonance dominated, with a general decreasing trend within the investigated collision energy range. The probability involving three potential energy surfaces is approximately two times as high as that on two potential energy surfaces. At low collision energies, the calculations on the ZPM2 surface produced much larger probability than that on the DMBE2 surface, but the difference was diminishing as the collision energy became high. The behavior of the probability on DMBE2/ZPM2 surfaces at low energies indicates that the ZPM2 surface dominates over the DMBE2 surface in the description of the process. However, the DMBE2 surface has been modified by removing the unreasonable barrier. The estimated quenching cross sections both on the ZPM2 surface and on the modified DMBE2 surface in the three-coupled-surface calculations agree with the experimental measurement. Also, a rather insensitive characteristic of the probability relative to the analytical function form of spin-orbit coupling is revealed. (C) 2004 American Institute of Physics.