Quantum dynamics scattering study of AB+CDE reactions:: A seven-dimensional treatment for the H2+C2H reaction

A time-dependent wave packet approach is presented for the quantum dynamics study of the AB+CDE reaction system for zero total angular momentum. A seven-degree-of-freedom calculation is employed to study the chemical reaction of H-2+C2H-->H+C2H2 by treating C2H as a linear molecule. Initial state selected reaction probabilities are presented for various initial rovibrational states. This study shows that the vibrational excitation of H-2 enhances the reaction probability, whereas the excitation of C2H has only a small effect on the reactivity. An integral cross section is also reported for the initial ground states of H-2 and C2H. The theoretical and experimental results agree with each other very well when the calculated seven-dimensional results are adjusted to account for the lower transition state barrier heights found in recent ab initio calculations. (C) 2003 American Institute of Physics.