Franck-condon factors for large aromatic molecules

1967 ◽  
Vol 7 (1) ◽  
pp. 69-72 ◽  
Author(s):  
K. Miller ◽  
J. N. Murrell
Keyword(s):  
Aromatic Molecules ◽  
Condon Factors ◽  
Franck Condon

Internal conversion in aromatic and N-heteroaromatic molecules

1965 ◽  
Vol 18 (10) ◽  
pp. 1589 ◽  
Author(s):  
JP Byrne ◽  
EF McCoy ◽  
IG Ross
Keyword(s):  
Theoretical Basis ◽  
Internal Conversion ◽  
Empirical Approach ◽  
Bending Vibrations ◽  
Condon Factor ◽  
Aromatic Molecules ◽  
Condon Factors ◽  
Semi Empirical ◽  
Franck Condon

A previous semi-empirical approach to the calculation of the rate of internal conversion, regarded as a tunnelling process, is reformulated on a sounder theoretical basis. Following Robinson and Frosch, tunnelling rates are correlated with Franck-Condon factors for the associated transition. The total Franck-Condon factor, S2max, is a product of three terms, associated respectively with skeletal stretching, CH stretching, and skeletal angle bending vibrations. The value of S2max may be controlled by one term only of the product, or by two or more (mixed tunnelling). Tunnelling rates should be slowed down by deuteration only when CH vibrations participate significantly; specific predictions are made here. Skeletal-angle bending vibrations are of negligible importance in internal conversion in aromatic molecules, but they are very significant in transitions between states of π,π* and n,π* type in heteroaromatics. Correlation between S2max and estimated tunnelling rates is encouraging for four aromatic molecules and certain monocyclic azines; but the failure of pyridine and pyridazine to show luminescence is still unexplained. The case of pyrazine is discussed in detail.

Identification of the photoelectron spectra of HFCS via computing Franck–Condon factors

2021 ◽  
pp. 113393
Author(s):  
Jia-Lin Chang ◽  
Wen-Hsin Kuo ◽  
Yun-Jhu Huang ◽  
Mu-Fong Chang ◽  
Jui-Yang Huang ◽  
...  
Keyword(s):  
Photoelectron Spectra ◽  
Condon Factors ◽  
Franck Condon

THEORETICAL TRANSITION PROBABILITIES FOR THE $\tilde{A}^{2}A_{1} -\tilde{X}^{2}B_{1}$ SYSTEM OF H2O+ AND D2O+ AND RELATED FRANCK–CONDON FACTORS BASED ON GLOBAL POTENTIAL ENERGY SURFACES

2005 ◽  
Vol 04 (01) ◽  
pp. 225-245 ◽  
Author(s):  
IKUO TOKUE ◽  
KATSUYOSHI YAMASAKI ◽  
SATOSHI MINAMINO ◽  
SHINKOH NANBU
Keyword(s):  
Potential Energy ◽  
Photoelectron Spectroscopy ◽  
Potential Energy Surfaces ◽  
Least Squares Method ◽  
Transition Probabilities ◽  
Three Dimensional ◽  
Equilibrium Geometry ◽  
Condon Factors ◽  
Energy Surfaces ◽  
Franck Condon

To elucidate the ionization dynamics, in particular the vibrational distribution, of H 2 O +(Ã) produced by photoionization and the Penning ionization of H 2 O and D 2 O with He *(2 3S) atoms, Franck–Condon factors (FCFs) were given for the [Formula: see text] ionization, and the transition probabilities were presented for the [Formula: see text] emission. The FCFs were obtained by quantum vibrational calculations using the three-dimensional potential energy surfaces (PESs) of [Formula: see text] and [Formula: see text] electronic states. The global PESs were determined by the multi-reference configuration interaction calculations with the Davidson correction and the interpolant moving least squares method combined with the Shepard interpolation. The obtained FCFs exhibit that the [Formula: see text] state primarily populates the vibrational ground state, as its equilibrium geometry is almost equal to that of [Formula: see text], while the bending mode (ν2) is strongly enhanced for the H 2 O +(Ã) state; the maximums in the population of H 2 O + and D 2 O + are approximately v2 = 11–12 and 15–17, respectively. These results are consistent with the distributions observed by photoelectron spectroscopy. Transition probabilities for the [Formula: see text] system of H 2 O + and D 2 O + show that the bending progressions consist primarily of the [Formula: see text] emission, with combination bands from the (1, v′2 = 4–8, 0) level being next most important.

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