Surface jumping: Franck-Condon factors and condon points in phase space

S. Kallush, Bilha Segev, A. V. Sergeev, E. J. Heller

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

We generalize the concept of Tully-Preston surface hopping to include larger jumps in the case that the surfaces do not cross. Instead of identifying a complex hopping point, we specify a jump between two locales in phase space. This concept is used here to find propensity rules for the accepting vibrational mode(s) in a radiationless vibronic relaxation transition. A model inspired by the S 2 → S 0 vibronic relaxation transition of the benzene molecule in which 30 modes of vibration compete for the electronic energy is studied within this approach. For this model, we show that almost all of the energy must go to a single C-H local stretching. The initial conditions for vibrations of this mode are a coordinate jump of the hydrogen atom toward the ring. All of the other modes undergo an almost vertical transition, in which the energy that they take is determined by their equilibrium displacement between the two surfaces. We observe that for a large energy gap the masses and frequencies become the defining parameters for choosing the accepting mode. Anharmonicities are very important when a competition between degenerate modes occurs. These conclusions are demonstrated by the specific model considered here but apply in general to any weak internal conversion process.

Original languageEnglish
Pages (from-to)6006-6016
Number of pages11
JournalJournal of Physical Chemistry A
Volume106
Issue number25
DOIs
Publication statusPublished - 27 Jun 2002
Externally publishedYes

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Vibration
vibration mode
Benzene
Hydrogen
internal conversion
Stretching
energy
hydrogen atoms
Energy gap
benzene
Atoms
Molecules
rings
electronics
molecules

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Surface jumping : Franck-Condon factors and condon points in phase space. / Kallush, S.; Segev, Bilha; Sergeev, A. V.; Heller, E. J.

In: Journal of Physical Chemistry A, Vol. 106, No. 25, 27.06.2002, p. 6006-6016.

Research output: Contribution to journalArticle

Kallush, S, Segev, B, Sergeev, AV & Heller, EJ 2002, 'Surface jumping: Franck-Condon factors and condon points in phase space', Journal of Physical Chemistry A, vol. 106, no. 25, pp. 6006-6016. https://doi.org/10.1021/jp014336m
Kallush, S. ; Segev, Bilha ; Sergeev, A. V. ; Heller, E. J. / Surface jumping : Franck-Condon factors and condon points in phase space. In: Journal of Physical Chemistry A. 2002 ; Vol. 106, No. 25. pp. 6006-6016.
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