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.

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.

The Visible Absorption Spectrum of Diatomic Calcium

1975 ◽  
Vol 53 (5) ◽  
pp. 472-485 ◽  
Author(s):  
Walter J. Balfour ◽  
Rodger F. Whitlock
Keyword(s):  
Absorption Spectrum ◽  
Potential Energy ◽  
Ground State ◽  
Electronic States ◽  
Visible Absorption Spectrum ◽  
Weakly Bound ◽  
Visible Absorption ◽  
Condon Factors ◽  
Calcium Vapor ◽  
Franck Condon

The electronic spectrum of calcium vapor has been photographed in absorption from 460 to 600 nm. A many line spectrum due to Ca2 has been identified from vibrational and rotational analyses and a total of 3800 lines involving 47 bands in the A1Σu+ ← X1Σg+ system of 40Ca2 have been assigned. Analysis shows that the X1Σg+ state is weakly bound with a dissociation energy De″ = 1075 ± 150 cm−1. The A1Σu+ state is considerably more stable. Term values, Dunham coefficients, and RKR potential energy curves have been determined for both electronic states, and Franck–Condon factors, with their dependence on rotation, have been evaluated. The more important constants for the ground state are ωe″ = 64.93 cm−1, ωexe″ = 1.07 cm−1, re″ = 0.4277 nm and those of the upper state are, [Formula: see text], [Formula: see text].Le spectre électronique de la vapeur de calcium a été photographié en absorption, de 460 à 600 nm. Un spectre de plusieurs raies provenant de Ca2 a été identifié à partir des analyses vibrationnelle et rotationnelle; on a déterminé les transitions correspondant à un total de 3800 raies appartenant à 47 bandes du système A1Σu+ ← X1Σg+ de 40Ca2. L'analyse montre que l'état X1Σg+ est faiblement lié, avec une énergie de dissociation

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*).

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

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.

Vibrational Transition Probabilities and Dissociation Energy of the PF Molecule

1993 ◽  
Vol 58 (4) ◽  
pp. 748-753 ◽  
Author(s):  
Narayanan Rajamanickam ◽  
Manuel Fernandez Gomez ◽  
Juan Jesus Lopez Gonzalez
Keyword(s):  
Dissociation Energy ◽  
Ground State ◽  
Potential Energy Curve ◽  
Transition Probabilities ◽  
Energy Curve ◽  
Vibrational Transition ◽  
Condon Factors ◽  
Franck Condon ◽  
Suitable Potential ◽  
Electronic Ground

The Franck-Condon factors (vibrational transition probabilities) and r-centroids have been evaluated by a more reliable numerical interogation procedure for the bands of b1Σ+ - X3Σ- system of the PF molecule, using a suitable potential. The dissociation energy, De = 318 kJ mol-1 for the electronic ground state of this molecule has been estimated by fitting the electronegativity function to the experimental potential energy curve.

An abinitio study of the A2A′—X2A″ vibronic transition in the free radical HNF

1983 ◽  
Vol 61 (11) ◽  
pp. 2500-2505 ◽  
Author(s):  
Miljenko Perić ◽  
Sigrid D. Peyerimhoff ◽  
Robert J. Buenker
Keyword(s):  
Free Radical ◽  
Potential Energy ◽  
Small Molecules ◽  
Large Angle ◽  
Vibrational Analysis ◽  
Electronic States ◽  
Measured Data ◽  
Vibronic Transition ◽  
Bending Modes ◽  
Linear Geometry

Potential energy curves for the two lowest electronic states X2A″ and A2A′(2Π in linear geometry) of HNF are calculated employing configuration interaction. A vibrational analysis of the A2A′—X2A″ transition is undertaken; stretching and bending modes are treated separately but vibronic coupling and large-angle bending is taken into consideration explicitly. The various vibronic levels including their K-type structure are compared with measured data wherever available and the results indicate that the prediction of vibronic spectra in small molecules on the basis of purely abinitio data is now within reach.

Rovibronic States in the X2Π State of the CCS− Anion

2003 ◽  
Vol 217 (3) ◽  
pp. 231-240 ◽  
Author(s):  
D. Panten ◽  
G. Chambaud ◽  
P. Rosmus ◽  
E. Riaplov ◽  
J. P. Maier
Keyword(s):  
Ground State ◽  
Three Dimensional ◽  
Equilibrium Geometry ◽  
Energy Functions ◽  
Potential Energy Functions ◽  
Condon Factors ◽  
Franck Condon ◽  
Electronic Affinity ◽  
Electronic Ground ◽  
Photodetachment Spectrum

AbstractThree-dimensional potential energy functions have been generated ab initio for the X2Π electronic ground state of CCS− and used in variational Renner–Teller calculations including electron spin. Rovibronic levels (J=P) for J≤5/2 are given for energies up to 4000cm−1. The pattern of the levels is compared with that of CCO−. In the case of CCS− the quartic force fields, equilibrium geometry, electric dipole moment, the electronic affinity and the Franck–Condon factors for the X2Π(CCS−) → X3Σ− (CCS) photodetachment spectrum are calculated.

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