Agostini, F., Abedi, A., Suzuki, Y., Min, S. K., Maitra, N. T., Gross, E. K. U.
The exact forces on classical nuclei in non-adiabtic charge transfer
Journal of Chemical Physics 141, (8),pp 084303/1-17 (2015)
The decomposition of electronic and nuclear motion presented in Abedi et al. [Phys. Rev. Lett.
105, 123002 (2010)] yields a time-dependent potential that drives the nuclear motion and fully
accounts for the coupling to the electronic subsystem. Here, we show that propagation of an
ensemble of independent classical nuclear trajectories on this exact potential yields dynamics that
are essentially indistinguishable from the exact quantum dynamics for a model non-adiabatic charge
transfer problem. We point out the importance of step and bump features in the exact potential that
are critical in obtaining the correct splitting of the quasiclassical nuclear wave packet in space after
it passes through an avoided crossing between two Born-Oppenheimer surfaces and analyze their
structure. Finally, an analysis of the exact potentials in the context of trajectory surface hopping
is presented, including preliminary investigations of velocity-adjustment and the force-induced
decoherence effect.
TH-2015-04