The spectroscopy of H2CS. 1. CS stretch potential curves for singlet states of planar H2CS, obtained by ab initio multireference CI methods

1995 ◽  
Vol 73 (1-2) ◽  
pp. 18-34 ◽  
Author(s):  
M. R. J. Hachey ◽  
F. Grein
Keyword(s):  
Dipole Moments ◽  
Oscillator Strengths ◽  
Excitation Energies ◽  
Valence States ◽  
Singlet States ◽  
Symmetry Species ◽  
Condon Factors ◽  
Combination Modes ◽  
Franck Condon ◽  
Potential Curves

For planar H2CS, (C2ν), the CS stretch potential curves were obtained for the four to six lowest singlet states of each symmetry species by using multireference CI methods. Included were the (n, 4s), (n, 4p), (n, 3d), (π, 4s), and (π, 4p) Rydberg as well as the (n, π*), (π, π*), (σ, π*), (n, σ*), (n0, π*2), and (nπ, π*2) valence states. Vertical and adiabatic excitation energies, equilibrium CS distances, vibrational frequencies for the CS stretching mode, dipole moments, oscillator strengths, and Franck–Condon factors were evaluated and found to be in good agreement with known experimental data. The role of the 1(π, π*) state that diabatically crosses all 1A1 states, including the n2 ground-state configuration, causing many interactions with other states, has been given special attention. The following reassignments and predictions are of interest. (i) A switch of Ẽ and [Formula: see text], with 1A1(n, 4py) corresponding to the Ẽ bands and 1B2(n, 4pz) corresponding to the [Formula: see text] bands is suggested, based on the energetic ordering. (ii) Because of strong Franck–Condon factors, hot bands are suggested to play an important role in the analysis of the CS stretch progression of [Formula: see text]. (iii) The [Formula: see text] system, only studied in low resolution, is predicted to have high intensity and be perturbed due to the crossing of (π, π*) with (n, 4py) in the vertical region. The CS stretch bands should be observable. (iv) Observed combination modes in the [Formula: see text] system may be due to vibronic mixing of (π, π*) with (σ, π*).

A theoretical study of the B′2Σ+–X2Σ+ band system in MgH and MgD

1979 ◽  
Vol 57 (8) ◽  
pp. 1178-1184 ◽  
Author(s):  
M. L. Sink ◽  
A. D. Bandrauk
Keyword(s):  
Dipole Moment ◽  
Theoretical Study ◽  
Transition Probabilities ◽  
Band System ◽  
Dipole Moments ◽  
Electronic States ◽  
Oscillator Strengths ◽  
Moment Functions ◽  
Condon Factors ◽  
Franck Condon

Ab initio Cl calculations of the transition moment for the B′2Σ+–X2Σ+ transition in MgH are reported. Theoretical values for the Franck–Condon factors, band strengths, band oscillator strengths, and transition probabilities have been computed for MgH and MgD. An analysis of our results for this system predicts many bands to be observable which have not yet been identified. Dipole moment functions and vibrationally averaged dipole moments are given for the X2Σ+, A2Π, and B′2Σ+ electronic states.

Further Analyses of Infrared 1Π → 1Σ Bands of 89Y127I: New Spectroscopic Data on States up to υ"=7 and υ'=4

1984 ◽  
Vol 39 (1) ◽  
pp. 27-31 ◽  
Author(s):  
A. Bernard ◽  
R. Gravina
Keyword(s):  
Spectroscopic Data ◽  
Molecular Constants ◽  
Dense Structure ◽  
Normal Distributions ◽  
Synthetic Spectra ◽  
Condon Factors ◽  
Emission System ◽  
Franck Condon ◽  
Potential Curves ◽  
Rms Errors

This paper deals with the extension of a recent study of the infrared 1Π → 1Σ emission system of the YI molecule (1). Thanks to the extreme regularity of the structure, rotational analyses can be completed for the previous 3-1, 2-0, 1-0, 0-0 and 0-1 bands and extended to 11 more bands detected step by step from their synthetic spectra (owing to the extremely dense structure). A unique and consistent set of accurate rotational constants is derived for both states, up to the levels υ" = 7 and υ' = 4, from the reduction of 5772 line wavenumbers in the bands 3-1, 2-0, 1-0, 0-0. 0-1. 0-2, 1-3, 2-4, 2-5, 3-6 and 4-7, the υ-connected bands being fitted simultaneously. The 57 estimated constants allow to reproduce the observed spectra with typical weighted rms errors between 4 and 5 mK. When using these constants to generate the bands 2-1, 1-2, 3-3, 1-4 and 3-5, ~1300 lines can be picked out whose experimental positions relatively to the predicted ones correspond to quite equivalent rms errors with nearly normal distributions of the residuals, therefore ensuring the reliability of the analysis. Molecular constants at equilibrium are derived; improvments are significant, particularly for vibration. Franck-Condon factors and r-centroïds appropriate to RKR potential curves are given. The observed bands correspond to those which are predicted to be the strongest ones in each υ'-progression.

Low-lying electronic states of CuBr

2001 ◽  
Vol 79 (2-3) ◽  
pp. 299-343 ◽  
Author(s):  
T Hirao ◽  
P F Bernath
Keyword(s):  
Fourier Transform ◽  
Electronic States ◽  
Buffer Gas ◽  
Fourier Transform Spectrometer ◽  
Molecular Constants ◽  
Expansion Formula ◽  
Condon Factors ◽  
Mass Dependent ◽  
Franck Condon ◽  
Potential Curves

The A1Π – X1Σ+ and B1Σ+ – X1Σ+ transitions of copper monobromide, CuBr, were recorded with a Fourier transform spectrometer. The emission was generated by using a hollow cathode discharge of Ar buffer gas and a mixture of Cu and CuBr powders. The mass-dependent Dunham expansion formula was used to obtain improved molecular constants for the ground, A and B states. These molecular constants provided RKR potential curves and Franck–Condon factors for the A–X and B–X transitions.PACS No. 35.80 transitions. PACS No. 35.80

Abinitio SCF and MRD-CI description of the A2A′ – X2A″ transition of the as yet unknown HNCl molecule

1985 ◽  
Vol 63 (11) ◽  
pp. 3264-3268 ◽  
Author(s):  
Britta L. Schürmann ◽  
Robert J. Buenker
Keyword(s):  
Ground State ◽  
Mode Coupling ◽  
Vibrational Analysis ◽  
Electronic States ◽  
Oscillator Strengths ◽  
Fundamental Frequencies ◽  
Condon Factors ◽  
Franck Condon ◽  
Linear Geometry ◽  
Made In

Abinitio potential curves of the X2A″ ground state and the first excited A2A′ state (2Π in linear geometry) of HNCl are calculated employing multi-reference single- and double-excitation configuration interaction in order to aid in the search for this system experimentally. A vibrational analysis (frequencies and Franck–Condon factors) of the A2A′ – X2A″ transition is undertaken by neglecting coupling between the various modes. Diagonal and off-diagonal force constants together with the fundamental frequencies have been calculated by including mode coupling for both electronic states, and oscillator strengths and radiative lifetimes are also obtained. Comparison with theoretical and experimental results for other isovalent systems is also made in order to establish trends in this group of HAB systems.

scholarly journals Calculating Franck Condon Factor and Potential Curves for X2Σ+-A2Π System of BeBr Molecule

2015 ◽  
Vol 52 ◽  
pp. 5-10
Author(s):  
Adil Nameh Ayaash
Keyword(s):  
Excited State ◽  
Potential Function ◽  
Dissociation Energy ◽  
Ground State ◽  
Spectroscopic Properties ◽  
Spectroscopic Constants ◽  
Condon Factor ◽  
Condon Factors ◽  
Franck Condon ◽  
Potential Curves

The present work concerns by study of spectroscopic properties for Beryllium monobromide BeBr. Franck Condon Factor of BeBr molecule had been calculated theoretically for ground state X2Σ+ and excited state A2Π by special integrals by depending on spectroscopic constants for this molecule. The Dissociation energy and potential curves of this molecule is studied in this work by using Hua potential function, the results of potential curves and Franck Condon Factors converge with other researchers results.

Possible schemes of photoassociation processes in the KLi molecule with newly calculated potential energy curves

Open Physics ◽  
2013 ◽  
Vol 11 (9) ◽  
Author(s):  
Łukasz Miądowicz ◽  
Patryk Jasik ◽  
Józef Sienkiewicz
Keyword(s):  
Potential Energy ◽  
Electronic State ◽  
Dipole Moments ◽  
Potential Energy Curves ◽  
Ground Electronic State ◽  
Transition Dipole ◽  
Transition Dipole Moments ◽  
Condon Factors ◽  
Franck Condon ◽  
Calculated Potential Energy

AbstractWe present four promising schemes for photoassociative formation of KLi molecule in its ground electronic state. Analysis is based on newly calculated adiabatic potentials supported by transition dipole moments and Franck-Condon factors.

Vertical electronic spectra of the isovalent molecules H2CNH, H2SiNH, H2CPH, and H2SiPH on the basis of MRD-CI calculations

1985 ◽  
Vol 63 (7) ◽  
pp. 1594-1608 ◽  
Author(s):  
Pablo J. Bruna ◽  
Volker Krumbach ◽  
Sigrid D. Peyerimhoff
Keyword(s):  
Large Scale ◽  
Dipole Moments ◽  
Experimental Investigations ◽  
Equilibrium Geometry ◽  
Rydberg Series ◽  
Uv Spectrum ◽  
Excitation Energies ◽  
Vertical Excitation ◽  
Valence States ◽  
Ci Calculations

Large-scale multi-reference single and double-excitation configuration interaction (MRD-CI) calculations are employed for the study of the isovalent compounds H2CNH, H2SiNH, H2CPH, and H2SiPH in their ground state equilibrium geometry. The dipole moments and charge distributions are given. The vertical excitation energies to the intra-valence states 3.1(n, π*) and 3.1(π, π*) and to the first members of the Rydberg series originating from n and π MO's respectively are predicted; the first two ionization potentials and the Rydberg term values are also calculated. In H2CNH, mixing of Rydberg and valence-shell states with CN stretching is analyzed. The trends in relative stability of electronic and ionized states can be directly related to increased orbital stability of n relative to π as soon as a first-row constituent is replaced by a second-row atom. The calculations explain the diffuse character of the uv spectrum of imines; they treat the molecules H2SiNH and H2SiPH for the first time and present a large number of data for all four molecules which can serve as a basis for future experimental investigations on these and related compounds.

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