Theory Department
Max Planck Institute of Microstructure Physics
Agostini, F., Min, S. K., Abedi Khaledi, A., Gross, E. K. U.
Quantum-classical nonadiabatic dynamics: Coupled- vs independent-trajectory methods
Journal of Chemical Theory and Computation 12, (5),pp 2127-2143 (2016)
Trajectory-based mixed quantum-classical approaches to coupled electron-nuclear dynamics suffer from well-studied problems such as the lack of (or incorrect account for) decoherence in the trajectory surface hopping method and the inability of reproducing the spatial splitting of a nuclear wave packet in Ehrenfest-like dynamics. In the context of electronic nonadiabatic processes, these problems can result in wrong predictions for quantum populations and in unphysical outcomes for
the nuclear dynamics. In this paper, we propose a solution to these issues by approximating the coupled electronic and nuclear equations within the framework of the exact factorization of the electron-nuclear wave function. We present a simple quantumclassical scheme based on coupled classical trajectories and test it against the full quantum mechanical solution from wave packet
dynamics for some model situations which represent particularly challenging problems for the above-mentioned traditional methods.
TH-2016-14