Ab initio calculations of radiationless transitions between excited and ground singlet electronic states of ethylene
- 1 February 1998
- journal article
- research article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 108 (5), 2044-2055
- https://doi.org/10.1063/1.475584
Abstract
General expressions for internal conversion (IC) rate constant calculations have been derived by taking into account displacements, distortions, and rotation (mixing) of normal modes. The electronic part of the rate constant has been computed through the ab initio calculations of vibronic coupling. The corresponding expressions for the simplest two-mode case as well as for the general -mode case have been derived. We demonstrate the effect of rotated (mixed) normal modes on the IC rate constants based on a model consisting of one promoting and two mixed modes. The dynamics of excited states of has been investigated based on the internal conversion mechanism. The calculated rate of internal conversion show that the lifetimes of the excited and states of are on the picosecond scale. We predict that if the molecule is excited to a Rydberg state, it relaxes to the ground state via the cascade mechanism,
Keywords
This publication has 30 references indexed in Scilit:
- On the theoretical investigation of vibronic spectra of ethylene by ab initio calculations of the Franck–Condon factorsThe Journal of Chemical Physics, 1996
- Radiationless Transitions between the First Excited Triplet State and the Singlet Ground State in Ethylene: A Theoretical StudyThe Journal of Physical Chemistry, 1996
- Photodissociation of ethylene at 193 nmThe Journal of Chemical Physics, 1992
- Nonadiabatic investigation of the V–N spectrum of ethylene in a new diabatic representationThe Journal of Chemical Physics, 1983
- Ab initiodetermination of vibrational band intensitiesMolecular Physics, 1980
- Study of vibronic, spin-orbit and vibronic-spin-orbit couplings of formaldehyde with applications to radiative and non-radiative processesProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1976
- Radiationless transitions in isolated moleculesThe Journal of Chemical Physics, 1973
- Dependence of Radiationless Decay Rates in Polyatomic Molecules upon the Initially Selected Vibronic State: General Theory and ApplicationThe Journal of Chemical Physics, 1972
- The energy gap law for radiationless transitions in large moleculesMolecular Physics, 1970
- The Intensities of the Symmetry-forbidden Electronic Bands of BenzeneProceedings of the Physical Society. Section A, 1956