Les intensités des raies rotationnelles du système b1Σ+ – X3Σ− de la molécule NF

1986 ◽  
Vol 64 (11) ◽  
pp. 1529-1533 ◽  
Author(s):  
M. Vervloet ◽  
J. K. G. Watson
Keyword(s):  
Fourier Transform ◽  
Ab Initio ◽  
Least Squares ◽  
Relative Size ◽  
Fourier Transform Spectrometer ◽  
Line Intensities ◽  
Transition Moments ◽  
Least Squares Fit

The 0–0 band of the b1Σ+ – X3Σ− system of the NF molecule has been measured in emission using a Fourier-transform spectrometer. The line assignments of Douglas and Jones are confirmed, but their statement regarding the relative size of the parallel and perpendicular transition moments is incorrect. From a least squares fit of the line intensities, we determine the value μ1/μ0 = 0.261 for the ratio of the perpendicular (μ1) and parallel (μ0) transition moments. This value lies between two recent ab initio estimates, 0.96 and 0.049.

High-Resolution Infrared Spectrum of Diazirine, H2CN2. Rovibrational Analysis of the Methylene Deformation Band

1988 ◽  
Vol 43 (4) ◽  
pp. 331-337 ◽  
Author(s):  
A. Gambi ◽  
A. Baldacci ◽  
S. Giorgianni
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Infrared Spectrum ◽  
Least Squares ◽  
Deformation Band ◽  
Fourier Transform Spectrometer ◽  
Centrifugal Distortion ◽  
Molecular Constants ◽  
Centrifugal Distortion Constants

Abstract The infrared spectrum of diazirine has been recorded at Doppler resolution with a high informa­tion Fourier transform spectrometer. The ν3 fundamental has been reinvestigated and the overall assignment of the rovibrational transitions has been carried out. From the least-squares analysis a more accurate set of molecular constants including the sextic centrifugal distortion constants has been determined for the level υ3 = 1 and will be reported here. The higher resolution achieved here allowed the assignment of weaker lines and many Q branch transitions. Moreover many blended lines have now been resolved and could be properly assigned.

H218O: line positions and intensities between 9500 and 11 500 cm−1. The (041), (220), (121), (300), (201), (102), and (003) interacting states

1987 ◽  
Vol 65 (7) ◽  
pp. 777-789 ◽  
Author(s):  
J. -P. Chevillard ◽  
J. -Y. Mandin ◽  
J.-M. Flaud ◽  
C. Camy-Peyret
Keyword(s):  
Fourier Transform ◽  
Water Vapor ◽  
Energy Levels ◽  
Rotational Energy ◽  
Fourier Transform Spectrometer ◽  
Vibrational States ◽  
Line Intensities ◽  
Line Positions ◽  
Average Uncertainty

The spectrum of 18O-enriched water vapor has been recorded between 9500 and 11 500 cm−1, with the aid of a Fourier-transform spectrometer. Its analysis has allowed the determination of 419 accurate rotational energy levels belonging to seven interacting vibrational states of H218O: (041), (220), (121), (300), (201), (102), and (003). Moreover, 622 line intensities belonging to the 4ν2 + ν3, 2ν1 + 2ν2, ν1 + 2ν2 + ν3, 3ν1, 2ν1 + ν3, ν1 + 2ν3, and 3ν3 bands have been measured with an average uncertainty of 6%.

Calculated energy levels and intensities for the ν1 + ν2 and 3ν2 bands of HDO

1986 ◽  
Vol 64 (6) ◽  
pp. 736-742 ◽  
Author(s):  
A. Perrin ◽  
C. Camy-Peyret ◽  
J. -M. Flaud
Keyword(s):  
Least Squares ◽  
Strong Influence ◽  
Energy Levels ◽  
Rotational Energy ◽  
Transition Moment ◽  
Synthetic Spectrum ◽  
Vibrational States ◽  
Line Intensities ◽  
Least Squares Fit ◽  
Line Positions

A Hamiltonian taking into account both Fermi- and Coriolis-type interactions has been used to reproduce very satisfactorily the available rotational energy levels of the (1 1 0) and (0 3 0) interacting vibrational states of HDO. Then, a least squares fit of the line intensities of the ν1 + ν2 and 3ν2 bands of HDO has provided us with the transformed transition-moment operators of these two bands expanded in a form adapted to the Cs symmetry type of the molecule. The strong influence of the resonances on both line positions and intensities has been exemplified. Finally, the synthetic spectrum of the ν1 + ν2 and 3ν2 hybrid bands of HDO has been computed.

A Theoretical Survey of 4s–4p and 4p–4d Transitions in Nickel-Like Ions

1988 ◽  
Vol 102 ◽  
pp. 299-302
Author(s):  
J.-F. Wyart
Keyword(s):  
Ab Initio ◽  
Least Squares ◽  
Generalized Least Squares ◽  
Potential Method ◽  
Current Interest ◽  
Isoelectronic Sequence ◽  
Energy Parameters ◽  
Least Squares Fit ◽  
Charge States ◽  
A Current

AbstractMulticharged ions in the isoelectronic sequence of nickel have a current interest, due to possible population inversions occuring between excited levels. The identification of 4s-4p and 4p-4d transitions was recently extended up to Mo XV, owing to new experiments performed at I.S.A.N., Troitsk (USSR), and to the subsequent interpretation of the first excited configurations by means of the Slater-Condon method and generalized least squares fit of energy parameters along a sequence. For predicting transitions in higher charge states, the same configurations have been studied ab initio by using the relativistic parametric potential method and selected transitions involving short-lived lower levels are given for 14 ions in the sequence from Sr XI to Eu XXXVI.

x–y Coriolis interaction in the ν5 and ν8 bands of propyne-d3

1993 ◽  
Vol 71 (10) ◽  
pp. 1684-1688 ◽  
Author(s):  
Geetha Rajappan ◽  
V.A. Job
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Fermi Resonance ◽  
Coriolis Interaction ◽  
Line Intensities ◽  
Transition Moments ◽  
Relative Value ◽  
Fourier Transform Spectra

High resolution Fourier transform spectra of the ν5 and ν8 bands of CD3C≡CH have been recorded and analyzed taking into account the strong x–y Coriolis interaction between these fundamentals. Fermi resonance of the ν8 state with the ν9 + ν10 state, l-type doubling interaction between the ± l components of ν8 and a weak k-type doubling interaction between the ν5 and ν8 states have also been included in the perturbation treatment. The parameters of the ν5 and ν8 states as well as some of the parameters of the unobserved ν9 + ν10 state have been determined. An estimate of the relative value of the transition moments has been obtained from the line intensities, which are strongly affected by the x–y Coriolis interaction.

scholarly journals β Cas: Simultaneous Stromgren Photometry

1993 ◽  
Vol 137 ◽  
pp. 730-732 ◽  
Author(s):  
E. Rodriguez ◽  
A. Rolland ◽  
P. Lopez De Coca ◽  
R. Garrido ◽  
S.F. Gonzalez-Bedolla
Keyword(s):  
Fourier Transform ◽  
Least Squares ◽  
Discrete Fourier Transform ◽  
Sierra Nevada ◽  
Comparison Star ◽  
Transform Method ◽  
Principal Peak ◽  
Simultaneous Measurements ◽  
Least Squares Fit ◽  
Light Maximum

The observations were carried out in August, 1983 using the 75 cm telescope at Sierra Nevada Observatory in Spain. This telescope is equipped with a six-channel uvbyβ photometer for simultaneous measurements in uvby and the narrow and wide Hβ channels, respectively. The observations were collected during four nights in the four uvby filters and one more night was devoted to measuring β Cas in the n and w bands of the Hβ Crawford system. In all cases, a calibrated neutral filter was used for β Cas. The comparison star was Cl=HR 9085 (V=5.m55, F0III).The analysis of frequencies was carried out using the Discrete Fourier Transform method, as described in López de Coca et al. (1984), to the observational uvby points collected. The periodograms showed a principal peak at v=9.91 cd−l. After prewhitening for this frequency, the resulting periodograms did not show any trace of another peak, suggesting the monoperiodic nature of this star, in agreement with Antonello et al. (1986). Under the assumption of monoperiodicity of β Cas, the classical O-C method can easily be applied. Nine times of maxima were obtained for the four nights by using the method described in Rodriguez et al. (1990), where each light maximum has been derived as an average over the four uvby bands. When the O-C method was applied, the least squares fit converged to a linear ephemeris with the following elements: To=2445568.d5097 (±0.d0007) and Po=0.d10091 (±0.d00002). This linear ephemeris satisfactorily reproduces our data of β Cas.

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