Accurate quantum-mechanical rate constants for a linear response Azzouz-Borgis proton transfer model employing the multilayer multiconfiguration time-dependent Hartree approach

The multilayer multiconfiguration time-dependent Hartree (ML-MCTDH) method is applied to simulate the quantum dynamics and thermal rate constant of the Azzouz-Borgis model of proton transfer in a polar solvent. To this end, the original atomistic potential is mapped to a system-bath model. Employing the flux correlation function formalism and importance sampling techniques, accurate quantum mechanical rate constants are obtained, which provide a benchmark for evaluating approximate approaches to study the quantum dynamics of condensed-phase chemical reactions. Furthermore, the validity of the mapping procedure is discussed based on the comparison of the classical dynamics of the original atomistic Azzouz-Borgis model and the mapped system-bath model. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3624342]