Showing papers by "Olga V. Naumenko published in 2013"

IUPAC critical evaluation of the rotational-vibrational spectra of water vapor, Part III: Energy levels and transition wavenumbers for H216O

Abstract: This is the third of a series of articles reporting critically evaluated rotational–vibrational line positions, transition intensities, and energy levels, with associated critically reviewed labels and uncertainties, for all the main isotopologues of water. This paper presents experimental line positions, experimental-quality energy levels, and validated labels for rotational–vibrational transitions of the most abundant isotopologue of water, H216O. The latest version of the MARVEL (Measured Active Rotational–Vibrational Energy Levels) line-inversion procedure is used to determine the rovibrational energy levels of the electronic ground state of H216O from experimentally measured lines, together with their self-consistent uncertainties, for the spectral region up to the first dissociation limit. The spectroscopic network of H216O containstwo components, an ortho (o) and a para (p) one. For o-H216O and p-H216O, experimentally measured, assigned, and labeled transitions were analyzed from more than 100 sources. The measured lines come from one-photon spectra recorded at room temperature in absorption, from hot samples with temperatures up to 3000 K recorded in emission, and from multiresonance excitation spectra which sample levels up to dissociation. The total number of transitions considered is 184 667 of which 182 156 are validated: 68 027 between para states and 114 129 ortho ones. These transitions give rise to 18 486 validated energy levels, of which 10 446 and 8040 belong to o-H216O and p-H216O, respectively. The energy levels, including their labeling with approximate normal-mode and rigid-rotor quantum numbers, have been checked against ones determined from accurate variational nuclear motion computations employing exact kinetic energy operators as well as against previous compilations of energy levels. The extensive list of MARVEL lines and levels obtained are deposited in the supplementary data of this paper, as well as in a distributed information system applied to water, W@DIS, where they can easily be retrieved.

IUPAC critical evaluation of the rotational-vibrational spectra of water vapor, Part III: Energy levels and transition

Abstract: This is the third of a series of articles reporting critically evaluated rotational– vibrational line positions, transition intensities, and energy levels, with associated critically reviewed labels and uncertainties, for all the main isotopologues of water. This paper presents experimental line positions, experimental-quality energy levels, and validated labels for rotational–vibrational transitions of the most abundant isotopologue of water, H2 16 O. The latest version of the MARVEL (Measured Active Rotational– Vibrational Energy Levels) line-inversion procedure is used to determine the rovibrational energy levels of the electronic ground state of H2 16

High sensitivity cavity ring down spectroscopy of NO2 between 7760 and 7917 cm−1

Abstract: The very weak absorption spectrum of the main isotopologue of nitrogen dioxide, 14N16O2, is investigated for the first time between 7760 and 7917 cm−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 αmin≈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 7904.3 cm−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 ( v , 1 v 2 ± 2 , v 3 ∓ 1 ) ↔ ( v , 1 v 2 , v 3 ) 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 .