Theoretical studies of the tunneling splitting of malonaldehyde using the multiconfiguration time-dependent Hartree approach

International audienceFull dimensional multi-configuration time-dependent Hartree calculations of the zero point energy and the tunneling splitting of malonaldehyde using a recently published potential energy surface [Y.Wang, B. J. Braams, J. M. Bowman, S. Carter, and D. P. Tew, J. Chem. Phys. 128, 224314 (2008)] are reported. The potential energy surface has been approximated by a modified version of the nmode representation and careful convergence check has been performed to ensure accurate results. The obtained value for the splitting (23.4 cm−1) is in acceptable agreement with the experimental value of 21.583 cm−1. The computed zero-point-energy is 14 670 cm−1 which is lower than previous results of Wang et al., but likely to be about 4 cm−1 too low because of shortcomings of the nmode representation of the potential. The energies reported in this abstract contain a correction to account for neglected vibrational angular momentum terms