A "Classical" Trajectory Driven Nuclear Dynamics by a Parallelized Quantum-Classical Approach to a Realistic Model Hamiltonian of Benzene Radical Cation

We explore the workability of a parallelized algorithm of time-dependent discrete variable representation (TDDVR) methodology formulated by involving "classical" trajectories on each DOF of a multi-mode multi-state Hamiltonian to reproduce the population dynamics, photoabsorption spectra and nuclear dynamics of the benzene radical cation. To perform such dynamics, we have used a realistic model Hamiltonian consists of five lowest electronic states ((XE1g)-E-2, (BE2g)-E-2, C(2)A(2u), (DE1u)-E-2, and (EB2u)-B-2) which are interconnected through several conical intersections with nine vibrational modes. The calculated nuclear dynamics and photoabsorption spectra with the advent of our parallelized TDDVR approach show excellent agreement with the results obtained by multiconfiguration time-dependent Hartree method and experimental findings, respectively. The major focus of this article is to demonstrate how the "classical" trajectories for the different modes and the "classical" energy functional for those modes on each surface can enlight the time-dependent feature of nuclear density and its' nodal structure. (C) 2010 Wiley Periodicals, Inc. Int J Quantum Chem 111: 2741-2759, 2011