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The constants involved in the rotational expansion of the transformed transition moment operators of the 2v2, v1 and v3 bands of H2 17O have been determined through a fit of 280 measured line intensities. The coefficients 1μx and 3μz of the expansion of the dipole moment with respect to normal coordinates have been deduced to be 1μx = -0.021500±0.00030 D and 3μz=0.09596±0.0012 D.Moreover, the knowledge of the transition moment operators has been used to compute the whole spectrum of the 2v2, v1 and v3 bands of H2 17O.

Using a Fourier transform spectrum in the region 1750-2400 cm-1, the intensity of about 60 lines of the 2v2 - v2, v1 - v2 and v3 - v2 hot bands have been measured. The constants involved in the rotational expansion of the transformed transition moment operators relative to these bands have been obtained through a fit of the measured line intensities, taking into account the interactions between the vibrational states (020), (100) and (001). For the first time, from these constants and results concerning the intensities for the v2, v1 + v2 and v2 + v3 bands the value of the coefficient 23μz of the expansion of the dipole moment with respect to normal coordinates has been determined to be:[image omitted].Moreover the knowledge of the transformed transition moment operators has been used to compute the whole spectrum of the 2v2 - v2, v1 - v2 and v3 - v2 bands.

Using high resolution Fourier transform spectra, the three fundamental bands v2, v1 and v3 of D2 32S and the v2 band of D2 34S have been analysed and an extensive set of rotational levels for the (010), (100) and (001) vibrational states of D232S and for the (010) state of D234S has been obtained. These experimental levels have been reproduced very satisfactorily using a single Watson type hamiltonian for the (010) rotational levels, and a hamiltonian which takes into account the strong Coriolis resonance between the two interacting states (100) and (001). As a result, precise vibrational energies and rotational and coupling constants for the three states (010), (100) and (001) of D232S and for the (010) state of D234S were obtained. In particular the following band centres have been determined: [image omitted]

High resolution Fourier transform spectra in the 8-200 cm-1 spectral region have been used to analyse the pure rotation spectrum of nitrogen dioxide. In this way, the spin rotation levels of the (000) state were accurately measured for Ka up to 14 and N up to 54. Using a hamiltonian which takes the spin-rotation and the hyperfine operators explicitly into account, it has been possible to derive a complete set of molecular parameters (rotational, spin-rotation and hyperfine constants) for the (000) state of 14N16O2 from these experimental data and from the available microwave measurements. Numerous perturbations due to the hyperfine Fermi contact operator were analysed as well as a local resonance [42 0 42, J = 41·5] ↔ [41 2 40, J = 41·5] due to the electron spin-rotation interaction. Finally, a synthetic spectrum of the (000) ← (000) band of 14N16O2 including all hyperfine transitions has been computed, covering the 0-235 cm-1 spectral region.

High resolution Fourier transform spectra have been used for an extensive analysis of the 2v1 + v2, v1 + v2 + v3 and v2 + 2v3 bands of H2 32S and H2 34S in the 6000-6500 cm-1 region. Using a hamiltonian which takes explicitly into account the Coriolis interaction between the rotational levels of the (111) vibrational state with those of the (210) and (012) vibrational states together with the Darling-Dennison interaction between the (012) and the (210) states, it has been possible to reproduce satisfactorily the rotational energy levels of these three interacting states, and a precise set of vibrational energies and rotational and coupling constants has been derived. Moreover, individual intensities of transitions belonging to the 2v1 + v2, v1 + v2 + v3 and v2 + 2v3 bands of H232S have been estimated, leading to the determination of the transition moment constants appearing in the expansion of the transformed transition moment operators of these three bands. Finally a complete listing of the positions and intensities of the H232S and H234S lines absorbing in the 1·6 μm region has been generated.

Hydrogen-oxygen flame spectra have been recorded from 2850 cm-1 to 6200 cm-1 with a high resolution Fourier transform spectrometer at a limit of resolution of about 0·015 cm-1, and the emission spectrum of hot water vapour has been obtained. The complete analysis of the v1, v3 and v2 + v3 bands has been performed. A large set of new higher rotational energy levels for the (000), (100), (001) and (011) vibrational states is reported. A discussion of the assignment problem and of the least squares method for deriving the energy levels from the observed transitions is detailed.

The 2v2, v1 and v3 bands of H216O occurring in the region 2930-4255 cm-1 were studied from a spectrum recorded with a high resolution Fourier transform spectrometer (resolution: 0·005 cm-1). The set of the observed transitions leads by a least squares method to the determination of very accurate values of the rotational levels belonging to the vibrational states (000), (020), (100), (001). From these levels, using Watson's Hamiltonian, we have obtained respectively 21 and 17 rotational constants for the states (000) and (020).

The constants involved in the rotational expansion of the transformed transition moment operator of the v2 band of H216O have been determined through a fit of about 110 measured line intensities. A comparison between theoretical and experimental values of these constants is given. The coefficient 2μx of the expansion of the dipole moment with respect to normal coordinates is deduced to be[image omitted]Moreover, a knowledge of the transformed transition moment operator has been used to compute the whole spectrum of the v2 band.

The spectra of hydrogen-oxygen and acetylene-oxygen flames have been recorded on a Fourier transform spectrometer in the region 6200-9100 cm-1 with a resolution of 0·015 cm-1. In this region, we have performed a detailed analysis of the 2v2 + v3, v1 + v3, v1 + v2 + v3 - v2 and v1 + v2 + v3 bands. A primary motive for this study was to obtain higher rotational energy levels for the (021), (101) and (111) vibrational states. Moreover an extensive set of rotational levels of the (010) vibrational state has been deduced from the combined study of hot bands involving the (011), (021) and (111) vibrational states. A room-temperature absorption spectrum of water recorded on a Fourier transform spectrometer in the region 1750-2300 cm-1 (resolution 0·005 cm-1) has also been used to confirm the analysis.

High resolution Fourier transform spectra of the v2 band of HD 32S have been analysed and precise vibrational energy and rotational constants determined. The principal results (in cm-1) are: E (010) = 1032·7152, A (010) = 10·027 134 06, B (010) = 5·024 561 818, C (010) = 3·191 229 031.