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The very weak absorption spectrum of the main isotopologue of nitrogen dioxide, 14N16O2, is investigated for the first time between 7760 and 7917cm−1. The studied region corresponds to the highest energy range of the vibrational spectra of 14N16O2 investigated so far at high spectral resolution. The absorption spectra were recorded by very high sensitivity Continuous Wave-Cavity Ring Down Spectroscopy with a noise equivalent absorption of α min ≈5×10−11 cm−1. The spectrum results from the superposition of the rovibrational transitions of the 2ν1+5ν2+ν3, 2ν1+ν2+3ν3 and 5ν1+ν3 bands at 7790.9, 7888.2 and 7904.3cm−1, respectively. The spectrum assignment and modeling were performed using the effective Hamiltonian approach, which involves altogether three bright – (2,5,1), (2,1,3) and (5,0,1) and three dark – (2,7,0), (2,3,2) and (5,2,0) states. As a result, 3020 rovibrational transitions were assigned including 51 extra lines of the 2ν1+3ν2+2ν3 and 5ν1+2ν3 bands. In this way, the overall set of 1494 spin-rotation energy levels were reproduced with an rms of 4.9×10−3 cm−1 for the (obs.−calc) deviations, leading to the determination of 66 fitted parameters. The effective Hamiltonian for the {(5,2,0), (2,3,2), (2,7,0), (2,5,1), (2,1,3), (5,0,1)} interacting states takes into account both the spin–rotation interactions within each vibrational state and C-type Coriolis and anharmonic resonances between different vibrational states, according to symmetry considerations. Indeed for NO2 the ↔ spin rotation energy levels are usually coupled through C-type Coriolis resonances, and accordingly the (2,7,0)↔(2,5,1)↔(2,3,2)↔(2,1,3) and (5,2,0)↔(5,0,1) interactions were included in the effective Hamiltonian model. Furthermore, these two blocks of interacting states are coupled by an additional C-type Coriolis and anharmonic resonances. Using the fitted values of the Hamiltonian parameters and the values of the 2ν1+5ν2+ν3, 2ν1+ν2+3ν3 and 5ν1+ν3 bands transition dipole moment operators determined from a fit of a selected set of experimental line intensities, a synthetic spectrum was generated for the entire investigated region and is provided as Supplementary material. [ABSTRACT FROM AUTHOR]

Abstract: The absorption spectrum of water vapor enriched by deuterium and oxygen-18 is analyzed in the 6000–9200cm−1 region. The spectrum has been recorded at room temperature with a Bruker IFS 120h Fourier transform spectrometer. More than 14,000 absorption lines were measured in the recorded spectrum. The vibration–rotation assignments were performed on the basis of previously published experimental energies and of variational calculations. Nine water species (H2 16O, HD16O, D2 16O, H2 18O, HD18O, D2 18O, H2 17O, HD17O and D2 17O) were found to contribute to the observed absorption. More than 3600 lines of 19 vibrational bands of D2 18O and about 4700 lines of 16 bands of HD18O with J as high as 19 and K a as high as 11 were assigned. The main part of the HD18O and D2 18O lines and all lines of HD17O and D2 17O were observed in the laboratory for the first time. The obtained vibration–rotation energy levels are compared with previous experimental studies and the results of variational calculations. [Copyright &y& Elsevier]

Abstract: The high-resolution Fourier-transform spectrum of the D2 16O molecule is recorded and analyzed in the region near (7360–8440cm−1) where the bands of the V=3 (V=v 1+v 2/2+v 3) polyad are located. A total of 2772 transitions have been assigned based on recent variational calculation of Shirin et al. [JQSRT 2008;109:549–58]. A set of 1094 energy levels (564 of which are new) is determined for nine vibrational states including those of newly reported (102) and (220) states. Calculations using an effective Hamiltonian are performed to establish reasonable ro-vibrational labeling of the observed energy levels. The latest variational calculation are found to agree well with the experiment for line positions (within 0.026cm−1 on average); however, the calculated intensities for transitions to upper energy levels which are in close resonance with other states can be distorted. [ABSTRACT FROM AUTHOR]

Abstract: The high resolution absorption spectrum of dideuterated water, D2O, has been recorded by Intracavity Laser Absorption Spectroscopy (ICLAS) in the 12850–13380cm−1 spectral region which is the higher energy region reported so far for this water isotopologue. Very high deuterium enrichment was necessary to minimize the HDO absorption lines overlapping the D2O spectrum. The achieved sensitivity (noise equivalent absorption α min ∼10−9 cm−1) allowed detecting transitions with line strengths on the order of 5×10−28 cm/molecule. The spectrum analysis, based on recent variational calculations has provided a set of 422 new rovibrational energy levels belonging to 11 vibrational states, including rotational sublevels for four new vibrational states and one level of the (091) highly excited bending state. The very weak (104)–(000) band at 13263.902cm−1, which is the highest D2 16O band currently observed, could be assigned despite the fact that the HDO absorption in the region is stronger by three orders of magnitude. The list of 996 D2 16O transitions is provided as Supplementary Material. [Copyright &y& Elsevier]

Abstract: Assignment of an HDO line list extracted from a recently measured H2O/HDO/D2O Fourier transform absorption spectrum recorded in the 11600–23000cm−1 region by Bach et al. (M. Bach, S. Fally, P.-F. Coheur, M. Carleer, A. Jenouvrier, A.C. Vandaele, J. Mol. Spectrosc. 232 (2005) 341–350.) is presented. More than 94% of the 3256 lines are given quantum number assignments and ascribed to line absorption by HDO; most of the remaining lines are actually due to D2O. High accuracy variational predictions of line positions and intensities are used for the spectral assignment process. Assignments to the ν 1 +5ν 3, 2ν 2 +5ν 3, ν 1 + ν 2 +3ν 3 and ν 1 +6ν 3 bands are presented for the first time. Comparisons are made with published ICLAS spectra covering the same spectral region and suggestions made for its recalibration. The results are used to illustrate the dynamical behaviour of highly excited vibrational states of HDO and to discuss previous vibrational assignments to high lying rotation–vibration states of this system. [Copyright &y& Elsevier]

Abstract: The weak absorption spectrum of dideuterated water, D2O, has been recorded by Intracavity Laser Absorption Spectroscopy (ICLAS) between 11400 and 11900cm−1. This spectrum is dominated by the 3ν 1 + ν 2 + ν 3 and the ν 1 + ν 2 +3ν 3 centered at 11500.25 and 11816.64cm−1, respectively. A total of 530 energy levels belonging to eight vibrational states were determined. The rovibrational assignment process of the 840 lines attributed to D2O was mostly based on the results of new variational calculations consisting in a refinement of the potential energy surface of Shirin et al. [J. Chem. Phys., 120 (2004) 206] on the basis of recent experimental observations, and a dipole moment surface from Schwenke and Partridge [J. Chem. Phys. 113 (2000) 6592]. The overall agreement between these calculations and the observed spectrum is very good both for the line positions and the line intensities. [Copyright &y& Elsevier]

Abstract: Very weak water vapor absorption lines have been investigated by intracavity laser absorption spectroscopy (ICLAS) in the 11335–11947 and 12336–12843cm−1 spectral regions dominated by the ν 1 +3ν 2 + ν 3 and ν 2 +3ν 3 bands, respectively. A detectivity on the order of α min ∼10−9 cm−1 was achieved with an ICLAS spectrometer based on a Ti: Sapphire laser. It allowed detecting transitions with an intensity down to 5×10−28 cm/molecule which is about 10 times lower than the weakest line intensities previously detected in the considered region. A line list corresponding to 1281 transitions with intensity lower than 5×10−26 cm/molecule has been generated. A detailed comparison with the line lists provided by the HITRAN database and by recent investigations by Fourier transform spectroscopy associated with very long multi pass cell is presented. The rovibrational assignment performed on the basis of the ab initio calculations of Schwenke and Partridge, has allowed for determining 176 new energy levels belonging to a total of 16 vibrational states. [Copyright &y& Elsevier]

Abstract: The absorption spectrum of dideuterated water, D2O, has been recorded between 8800 and 9520cm−1 by intracavity laser absorption spectroscopy (ICLAS) based on a vertical external cavity system emitting laser (VeCSEL) and by high sensitivity Fourier Transform spectroscopy. The combined analysis of the spectra has allowed attributing 1223 transitions to the D2O species. The spectrum assignment was performed on the basis of the recent results of variational calculations based on an optimized potential energy surface of D2O. A set of 687 energy levels was derived from transitions assigned to eight upper vibrational states, 577 of them being reported for the first time. A detailed line list has been generated. The line intensities were retrieved mainly from the FTS spectrum and the absolute integrated intensities of the 2v 1 + v 2 + v 3 and the v 2 +3v 3 bands dominating the spectrum have been determined. [Copyright &y& Elsevier]

The HDO absorption FT spectrum is recorded and analyzed in the 7500–8200 cm-1 spectral region. The high accuracy ab initio calculation of Schwenke and Partridge was successfully applied for spectrum assignment that resulted in derivation of 508 precise rovibrational energy levels for the (3 0 0), (0 3 1), (1 1 1), (0 6 0), (2 2 0), and (0 0 2) states, with 295 of them being reported for the first time. In particular, eight new energy levels, including the band center at 7914.3170 cm-1, were derived for the highly excited bending (0 6 0) state from transitions borrowing their intensities through local high-order resonance coupling with the (3 0 0) and (0 3 1) states. [Copyright &y& Elsevier]

The spectrum and mode shapes of the natural elastic vibrations of disk-shaped ZnSe crystals are studied. Twin modes are identified which are closely related to the stress-strain state of the material. [ABSTRACT FROM AUTHOR]

Highlights: [•] We made a new absorption HDO linelist in a wide region between 0 and 25,600cm−1. [•] About 3,000,000 of 720,000 line positions are estimated with experimental accuracy. [•] HDO–CO2 broadening coefficients and their temperature exponents are calculated. [•] Accurate variational intensities are provided for every line. [•] This HDO linelist is optimal for studying the martian and venusians atmospheres. [ABSTRACT FROM AUTHOR]

Abstract: The high resolution absorption spectrum of dideuterated water, D2 16O, has been recorded by Intracavity Laser Absorption Spectroscopy (ICLAS) in the 13600–14020cm−1 spectral region which is the highest energy region reported so far for this water isotopologue. Because the HD16O absorption is stronger by three orders of magnitude in the region under study, it was necessary to use high deuterium enrichment in order to minimize the HD16O absorption lines overlapping the D2 16O spectrum. With the high sensitivity achieved (noise equivalent absorption αmin ∼10−9 cm−1), transitions with line strengths on the order of 5×10−28 cm molecule−1 could be detected. The spectrum analysis, based on recent variational calculations has provided a set of 177 new rovibrational energy levels belonging to six vibrational states. The most complete set of 53 vibrational energy levels of D2 16O, including the three newly determined band origins, was constructed from an exhaustive review of the literature data. The fitting of the parameters of the vibrational effective Hamiltonian has allowed to reproduce the whole set of vibrational energies with an rms deviation of 0.055cm−1. This simple model gave consistent vibrational labels of the D2 16O states up to 18000cm−1. Above 15000cm−1, Fermi and Darling-Dennison resonance interaction were found to induce strong vibrational mixings of the wave functions in the normal mode basis, leading to ambiguous vibrational labeling. [Copyright &y& Elsevier]