||The vibrationally mediated photodissociation (VMP) of hydrogen peroxide [T. M. Ticich et al., J. Chem. Phys. 87, 5820 (1987)] is modeled. The two-photon VMP process proceeds via a highly vibrationally excited state on the ground electronic surface, and affords a unique view of the dynamics in the high energy region of the potential energy surface. We calculate, in a local mode basis set, the third OH stretch overtone wave function using the ground potential energy surface of Harding [L. B. Harding, J. Phys. Chem. 93, 8004 (1989)]. Although the overtone wave function is highly localized in the excitation mode, the delocalized tails which extend into the wide amplitude OO stretch region are crucial to the VMP mechanism. Interferences between zero-order states comprising these tails are shown to lead to a single state’s being excited, the latter suggested by the VMP spectrum. The low frequency torsional mode is seen to play an important role in the makeup of the wave function.