In the simulations, the dynamics of the six modes are described at the MCTDH level including all mode couplings (for the six-mode model) and the dynamics are propagated for a total of 5000 a.u. (120.9 fs). The initial state used in the dynamics is created from a ground state VSCF wave function obtained by using only the one-mode part of the reference potential and where the double well in the q 0 mode is replaced by a displaced harmonic potential. This harmonic potential is defined such that the harmonic frequency is 2493.55 cm -1 and the Gaussian wave function is centered around a displacement of 14.27 a.u. in the mass and frequency scaled coordinates used in the simulation. Thus, the initial state is a Hartree product of the VSCF modals obtained from the q 15 , q 17 , q 19 , q 37 , and q 41 one-mode cuts and a Gaussian modal displaced away from the double well minima of the enol form towards the TS. The harmonic potential and the corresponding VSCF modal in the q 0 mode are shown in Fig. .