scholarly journals Theoretical Investigations of Photoionization Efficiency of Naphthalene

2019 ◽  
Author(s):  
Chih-Hao Chin ◽  
Tong Zhu ◽  
John ZH Zhang
Keyword(s):  
Electronic Transition ◽  
Density Functional ◽  
Molecular Beam ◽  
Density Functional Theory Calculations ◽  
Harmonic Oscillators ◽  
Equilibrium Geometry ◽  
Complete Active Space ◽  
Adiabatic Representation ◽  
Condon Factors ◽  
Franck Condon

The equilibrium geometry and 48 vibrational normal-mode frequencies of the neutral and cationic ground state and the cationic first excited states of naphthalene isomers were calculated and characterized in the adiabatic representation by using the complete active space self-consistent field (CASSCF) and second order perturbation theory (CASPT2). Photoionization-efficiency (PIE) spectrum of molecular beam conditions in energy range 8 - 11 eV were determined by Kaiser et al. and they were analyzed using time-dependent density functional theory calculations (TDDFT). CASSCF calculations and PIE spectra simulations by one-photon excitation equations were used to optimize the cationic excited (D1) and neutral ground (S0) state structures of naphthalene isomers. The photoionization-efficiency curve was attributed to the S0  D1 electronic transition in naphthalene, and a curve origin was used at 8.14 eV. The ionization-induced geometry changes of the bases are consistent with the shapes of the corresponding molecular orbitals. The displaced harmonic oscillator approximation and Franck-Condon approximation were used to simulate the PIE curve of the D1  S0 transition of naphthalene, and the main vibronic transitions were assigned for the ππ* state. It shows that the vibronic structures were dominated by one of the xxx active totally symmetric modes, with v8 being the most crucial. This indicates that the electronic transition of the D1 state calculated in the adiabatic representation effectively includes a contribution from the adiabatic vibronic coupling through Franck-Condon factors perturbed by harmonic oscillators. The present method can adequately reproduce experimental PIE curve in the molecular beam condition.

scholarly journals Theoretical Investigations of Photoionization Efficiency of Naphthalene

2019 ◽  
Author(s):  
Chih-Hao Chin ◽  
Tong Zhu ◽  
John ZH Zhang
Keyword(s):  
Electronic Transition ◽  
Density Functional ◽  
Molecular Beam ◽  
Density Functional Theory Calculations ◽  
Harmonic Oscillators ◽  
Equilibrium Geometry ◽  
Complete Active Space ◽  
Adiabatic Representation ◽  
Condon Factors ◽  
Franck Condon

The equilibrium geometry and 48 vibrational normal-mode frequencies of the neutral and cationic ground state and the cationic first excited states of naphthalene isomers were calculated and characterized in the adiabatic representation by using the complete active space self-consistent field (CASSCF) and second order perturbation theory (CASPT2). Photoionization-efficiency (PIE) spectrum of molecular beam conditions in energy range 8 - 11 eV were determined by Kaiser et al. and they were analyzed using time-dependent density functional theory calculations (TDDFT). CASSCF calculations and PIE spectra simulations by one-photon excitation equations were used to optimize the cationic excited (D1) and neutral ground (S0) state structures of naphthalene isomers. The photoionization-efficiency curve was attributed to the S0  D1 electronic transition in naphthalene, and a curve origin was used at 8.14 eV. The ionization-induced geometry changes of the bases are consistent with the shapes of the corresponding molecular orbitals. The displaced harmonic oscillator approximation and Franck-Condon approximation were used to simulate the PIE curve of the D1  S0 transition of naphthalene, and the main vibronic transitions were assigned for the ππ* state. It shows that the vibronic structures were dominated by one of the xxx active totally symmetric modes, with v8 being the most crucial. This indicates that the electronic transition of the D1 state calculated in the adiabatic representation effectively includes a contribution from the adiabatic vibronic coupling through Franck-Condon factors perturbed by harmonic oscillators. The present method can adequately reproduce experimental PIE curve in the molecular beam condition.

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.

Franck-Condon factors for multidimensional harmonic oscillators

1998 ◽  
Vol 228 (1-3) ◽  
pp. 227-240 ◽  
Author(s):  
Per-Åke Malmqvist ◽  
Niclas Forsberg
Keyword(s):  
Harmonic Oscillators ◽  
Condon Factors ◽  
Franck Condon

An octacoordinated Nb atom in the NbAl8H8+ cluster

2021 ◽  
Author(s):  
Piero Ferrari ◽  
Hung Tan Pham ◽  
Jan Vanbuel ◽  
Andre Fielicke ◽  
Minh T. Nguyen ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Density Functional Theory ◽  
Infrared Spectroscopy ◽  
Density Functional ◽  
Molecular Beam ◽  
Density Functional Theory Calculations ◽  
High Symmetry ◽  
Functional Theory

The NbAl8H8+ cluster was formed in a molecular beam and characterized by mass spectrometry and infrared spectroscopy. Density functional theory calculations showed that its lowest-energy isomer is a high symmetry...

AN EXPERIMENTAL STUDY OF THE BAND INTENSITIES IN THE CN RED SYSTEM

1958 ◽  
Vol 36 (1) ◽  
pp. 127-133 ◽  
Author(s):  
R. N. Dixon ◽  
R. W. Nicholls
Keyword(s):  
Experimental Study ◽  
Carbon Tetrachloride ◽  
Electronic Transition ◽  
Transition Moment ◽  
Active Nitrogen ◽  
Electronic Transition Moment ◽  
System A ◽  
Condon Factors ◽  
Franck Condon

Experimental band intensities in the CN red system, A (2Πi) →X(2Σ+), have been measured using an active nitrogen – carbon tetrachloride source. Using calculated Franck–Condon factors qν′ν″ the electronic transition moment Re(r) is found to vary little over the range 1.04 < r < 1.27 Å.

Variation of the Electronic Transition Moment and the Effective Vibrational Temperature in 4800–6700-Å System of MnO Molecule

1971 ◽  
Vol 25 (5) ◽  
pp. 554-556
Author(s):  
Prem Shankar Dube ◽  
A. K. Chaudhry ◽  
G. D. Baruah ◽  
D. K. Rai
Keyword(s):  
Electronic Transition ◽  
Vibrational Temperature ◽  
Transition Moment ◽  
Electronic Transition Moment ◽  
Straight Line ◽  
Condon Factors ◽  
Effective Vibrational Temperature ◽  
Franck Condon ◽  
Photographic Photometry

The 4800–6700-Å system of MnO has been excited in an arc. Using the photographic photometry, the relative band intensities have been measured. The data were interpreted with the aid of Franck-Condon factors and r centroids. The electronic transition moment is found to vary according to the relation Re(r) = const (1- 3.192 r + 1.99 r2), where 1.736≤ r≤ 1.90 Å. The slope of the straight line plot of log ∑ v″ I/v4 against G'(ν') for ν' progression gives an estimate of effective vibrational temperature to be 3860 K.

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