## Abstract

Pericyclic reactions with energies E well above the potential energy barrier B (case E>B) proceed with quantum nuclear flux densities (j) which are essentially proportional to the nuclear densities ρ in the femtosecond time domain. This corresponds to the definition of classical (cl) mechanics, j_{cl}=_{cl}ρ_{cl}, with almost constant velocity v_{cl}. For the other case E<B, however, that is, in the domain of coherent tunneling, we discover the opposite trend, that is, (j) has maximum value close to the barrier where ρ is a minimum (in fact where ρ is close to zero). The general conclusion is that quantum mechanical nuclear flux densities may be at variance from traditional expectations based on classical trajectories. This prediction calls for experimental demonstration. The counter-intuitive proof-of-principle is demonstrated for a simple, one-dimensional model of the Cope rearrangement of semibullvalene.

Original language | English |
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Pages (from-to) | 1397-1404 |

Number of pages | 8 |

Journal | ChemPhysChem |

Volume | 14 |

Issue number | 7 |

DOIs | |

Publication status | Published - 2013 May 10 |

## Keywords

- molecular dynamics
- nuclear flux densities
- pericyclic reactions
- quantum reaction dynamics
- tunneling

## ASJC Scopus subject areas

- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry