The time-dependent wave packet method is used to study the exchange and abstraction processes for the $\mathrm{H}+{\mathrm{H}}_{\mathrm{2}}\mathrm{O}$ reaction with both OH bonds in the ${\mathrm{H}}_{\mathrm{2}}\mathrm{O}$ reactant treated as reactive bonds in full dimension. The calculation clearly shows that it is necessary to treat both OH bonds in this way in order to accurately investigate the exchange process. However, for the abstraction process, the spectator model works very well. Nonreactive treatment of one OH bond by using a few vibrational basis functions or even freezing the bond can yield very accurate abstraction reaction probability.

• Received 21 May 2002

DOI:https://doi.org/10.1103/PhysRevLett.89.103201