Abstract
Trajectory surface hopping (TSH) and ab initio multiple spawning are two commonly employed methods for simulating the excited-state dynamics of molecules. TSH portrays the dynamics of nuclear wavepackets by a swarm of independent classical trajectories, which can hop between electronic states. Ab initio multiple spawning, however, expresses nuclear wavepackets on the basis of traveling, coupled basis functions, whose number can be extended in the case of coupling between electronic states. In the following, we propose to compare the performance of these two methods to describe processes involving the explicit interaction of a molecule with laser pulses. We base this comparison on the LiH molecule, as it is compatible with numerically exact simulations using quantum dynamics. As recognized in earlier works, the limitations of TSH due to its inherent independent trajectory approximation are further enhanced when studying an explicit photoexcitation. While ab initio multiple spawning is also based on a series of approximations, the couplings between its traveling basis functions allow for a proper description of phenomena that TSH cannot describe with its inherent independent trajectory approximation, even when applying decoherence corrections. We show here for different in silico experiments involving laser pulses that ab initio multiple spawning overcomes the limitations experienced by TSH and offers an at least qualitative description of population transfer between electronic states.
Original language | English |
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Pages (from-to) | 3582-3591 |
Number of pages | 10 |
Journal | Journal of Physical Chemistry A |
Volume | 123 |
Issue number | 16 |
DOIs | |
Publication status | Published - 25 Apr 2019 |
Bibliographical note
Funding Information:B.M. acknowledges support from the Fonds National de la Recherche Scientifique, Belgium (F.R.S.-FNRS), and the University of Lieg̀ e. Computational resources have been provided by the Consortium des Equipements de Calcul Intensif (CECI), funded by the F.R.S.-FNRS under Grant No. 2.5020.11. B.F.E.C. acknowledges support from Durham University.
Publisher Copyright:
© 2019 American Chemical Society.