Dynamics of vibrationally assisted tunnelling in model multidimensional systems. Three routes involving the Fourier grid Hamiltonian method

Abstract

The multidimensional complex-scaled Fourier grid Hamiltonian (FGH) and time-dependent FGH method are invoked to study the dynamics of vibrationally assisted or subdued tunnelling in model two-dimensional systems that can mimick the behaviour of many real proton transfer systems. In the time-dependant description a Hartree-type meanfield method and a propagator method in a grid basis set are explored. The coupling between tunnelling and anharmonic vibrational modes are seen to affect the tunnelling rates in different ways depending upon the types and magnitudes of the coupling. Implications of our results with respect to H-atom or proton transfer reactions are considered.