Positions and Intensities in the 2nu4/nu1/nu3 Vibrational System of 14NH3 Near 3 µm

Line positions and line intensities of the nu1, nu3, and 2nu4 bands of 14NH3 were analyzed using line positions from 0.0054 cm-1 apodized resolution FT spectra recorded at Orsay and using line intensities from 0.011 cm-1 unapodized resolution FT spectra recorded at Kitt Peak National Observatory. About 2110 lines with J' </= 10 were assigned from which 1832 line positions were fitted using an effective rotation-inversion Hamiltonian to achieve an rms of 0.085 cm-1. Nearly 1000 line intensities were measured with an accuracy of 6% or better and modeled to 11 terms of dipole moment expansion to +/-9.4%. The bandstrengths of the nu1, nu3, and 2nu4 bands (determined for the first time in the case of the 2nu4 band) are, respectively, 23.6(2), 11.8(1), and 2.82(4) cm-2/atm at 296 K. A prediction of the line positions and intensities was generated for some approximately 2700 lines with intensities calculated greater than 1 x 10(-4) cm-2 atm-1 at 296 K, suitable for planetological purposes. Tentative assignments involving 22 upper state levels of 4nus2 were identified, but these were not included in the modeling at the present stage. The theoretical model and the set of programs developed for treating the infrared system nu1/nu3/2nu4 of ammonia are briefly discussed. Copyright 1999 Academic Press.

Lambda-Splittings and Line Intensities in the 3 <-- 1 Hot Band of 14N16O: The Spectrum of Nitric Oxide in the First Overtone Region

Intensities and Lambda-splittings have been measured for lines belonging to the 3 <-- 1 hot band of 14N16O. The vibrational transition moment and the Herman-Wallis coefficient have been determined. Hamiltonian constants have been calculated for the four vibrational states v = 0, 1, 2, and 3, and a synthetic spectrum has been generated in the first overtone region of NO, taking into account the hyperfine structure for the 2 <-- 0 band. Copyright 1998 Academic Press. Copyright 1998Academic Press

Lambda-Splittings and Line Intensities in the First Overtone of Nitric Oxide

Using Fourier transform spectra, absolute line parameters (positions, Lambda splittings, and intensities) have been measured in the two allowed subbands 2Pi1/2-2Pi1/2 and 2Pi3/2-2Pi3/2 of the 2 <-- 0 vibrational band of the 14N16O molecule. These line parameters have been compared with previous experimental results and with the values available in the current HITRAN database. The measured line intensities led to the determination of the transition dipole moment as well as the Herman-Wallis coefficients. Improved spectroscopic constants were also obtained for the v = 2 vibrational state. Copyright 1997 Academic Press. Copyright 1997Academic Press

Phase errors on interferograms: influence on the determination of positions, intensities, and widths of lines in the infrared

The effect of a phase error on line parameter measurements by using Fourier-transform spectra is studied, showing that, to obtain accurate results without modifying the interferogram, it is necessary to adjust a computed spectrum to an experimental spectrum in which the phase error is taken into account.

Measurements of collisional linewidths in the nu(2) band of H(2)O from Fourier-transformed flame spectra

The collisional widths of more than 200 transitions belonging to the v(2) band of the H(2)O molecule were measured by using the Fourier-transformed spectra of an air-methane flame at 2000 K. A nonlinear least-squares method was used to determine the line widths for a wide range of J (up to 28) and K(a) (up to 14) quantum number values. Finally, an analysis of the results as functions of J and K(a) is presented.

Rotational and vibrational dependences of collisional linewidths in the nnu(2)-(n-1)nu(2) hot bands of H2O from Fourier-transform flame spectra

The collisional widths of ~ 160 transitions belonging mainly to the 2nu(2)-nu(2), 3nu(2)-2nu(2), and 4nu(2)-3nu(2) hot bands of the H(2)(16)O molecule have been measured on Fourier-transform air-methane flame spectra at 2000 K and analyzed, showing a strong decrease in the collisional widths when the rotational quantum number J increases, as well as a nonnegligible decrease of the collisional widths when the nu(2) vibrational quantum number increases.

Observations and calculations of (12)C(16)O(2) perpendicular band intensities in the 13-microm region

We present here Fourier transform spectrometer measurements of the intensities of lines of (12)C(16)O(2) for the two bands centered at 720.2800 and 741.7243 cm(-1). In addition, a comparison is made to calculations using the direct numerical diagonalization method for these bands and other bands previously studied in the same spectral region. This comparison shows very good agreement (within a few percent).

Absolute line intensities in the 20002 ? 11102 and 12201 ? 03301 bands of (12)C(16)O(2)

Positions and intensities of lines belonging to the 20002 ? 11102 and 12201 ? 03301 bands of (12)C(16)O(2) have been measured from high resolution FTS spectra. The observed line positions confirm the values given in the HITRAN database and, for each band, the squared transition dipole moments have been determined, we believe for the first time.

Line intensities and broadening parameters of the 11101 ? 10002 band of (12)C(16)O(2)

Intensities and broadening parameters of lines belonging to the 11101 ? 10002 band of (12)C(16)O(2) have been measured using Fourier transform spectroscopy spectra. From the measured line intensities it has been possible to determine the variation with respect to m or J of the squared transition dipole moment |micro|(2) as |micro|(2) = 1.323 x 10(-3) [1 + 1.0 x 10(-3) m - 1.6 x 10(-5)J (J + 1)](2) for P- and R-branches and |micro| = 1.323x10-5 J(J(2) = 1.323 x 10(-3) [1 - 3.5 x 10(-3)[1 - 3.5 x 10-5] J(J + 1)](2) for the Q-branch. Moreover, self-, nitrogen-, and oxygen-broadening parameters have been measured and they are compared with previously published values.

Determination of line parameters from FTS spectra

We present a procedure that derives intensities and broadening parameters for isolated lines from Fourier transform spectra. These parameters are obtained by convolving the true line shape, as would be obtained with infinite resolution with an apparatus function deduced from the filtering function of the interferometer. To check this procedure, intensities and self-broadening parameter measurements of the P and R lines belonging to the 10011 ? 10002 band of (12)C(16)O(2) have been performed, and the values obtained are compared to previous results.