E. R. Polovtseva

Hydrogen sulfide absorption spectrum in the 5700-6600 cm -1 spectral region

High resolution FT absorption spectrum of H2S from 5700 to 6600 cm-1 was experimentally recorded and theoretically treated. As a result of the spectrum assignment 1100 precise energy levels were derived for the 2nd hexad interacting states of H232S, H233S, and H234S isotope species including the highly excited (050) state. These energy levels were modeled using Watson-type rotational Hamiltonian and taking into account Coriolis, Darling-Dennison and weak Fermi-resonance interactions inside polyad of interacting states. An average accuracy of the energy levels fitting is of 0.0019 cm-1 for the main isotope species. New evaluation of the band origin of the dark (012) state Ev = 6385.299cm-1 is obtained from the fitting process which agrees well with recent prediction by Naumenko et al. (J. Mol. Spectrosc. 50, 100-110 (2001)). Precise line intensity measurements were performed for more than 1200 absorption lines with accuracy varying from 1 to 7%. These intensities were modeled within 3.3% using wavefunctions derived in the process of the energy levels fitting. The transformed transition moment expansion with 29 terms for 1088 intensities was used. Detailed and accurate H2S absorption line list was generated in the HITRAN format for the analyzed spectral region.

Information system for molecular spectroscopy. 5. Ro-vibrational transitions and energy levels of the hydrogen sulfide molecule

This work considers the verification, systematization, and publication in the W@DIS information system of all published data acquired at the moment by various authors from the analysis of high resolution, ro-vibrational spectra of hydrogen sulfide and its isotopologues. The system interface allows prompt and efficient search for any required information by specified criteria. The W@DIS information system, in its present state, contains the most complete and reliable information on ro-vibrational transitions and energy levels of the hydrogen sulfide molecule as compared with other databases. The data systematized in this work may serve as a source of information for problems of theoretical spectroscopy and chemistry, atmospheric problems, and other applications.

Absorption spectrum of H2S between 7200 and 7890 cm-1

The high resolution absorption spectra of H2S have been recorded in the region 7200-7890 cm-1 with the McMath Fourier transform spectrometer located at Kitt Peak National Observatory. A careful analysis of the spectra led to derivation of 1080 precise energy levels for the 1st decade interacting states of H232S, H233S, and H234S isotope species. The energy levels were introduced into a least squares fit using a Hamiltonian which takes into account Coriolis, Darling-Dennison and Fermi-resonance interactions. Precise rotational and coupling parameters have been determined which reproduce the experimental energy levels with 0.0015 cm-1 for the main isotope species. The experimental band origin Ev=7419.9162 cm-1 for the super weak (220)-(000) band was obtained for the first time from the simultaneous analysis of cold (220)-(000) and hot (220)-(010) bands. Detailed and accurate H2S absorption line list was generated in the HITRAN format for the first decade spectral region.

MARVEL analysis of the measured high-resolution rovibrational spectra of C2H2

44 325 measured and assigned transitions of H2S, the parent isotopologue of the hydrogen sulfide molecule, are collated from 33 publications into a single database and reviewed critically. Based on this information, rotation-vibration energy levels are determined for the ground electronic state using the Measured Active Rotational-Vibrational Energy Levels (Marvel) technique. The ortho and para principal components of the measured spectroscopic network of H2S are considered separately. The verified set of 25 293 orthoand 18 778 paraH2S transitions determine 3969 ortho and 3467 para energy levels. The 1email: katy.chubb.14@ucl.ac.uk 2email: j.tennyson@ucl.ac.uk Preprint submitted to Elsevier December 31, 2018 Marvel results are compared with alternative data compilations, including a theoretical variational linelist.

D2O absorption spectrum in the region near 0.95 μm: the ν1 + 3ν3 rotational-vibrational band

The D2О absorption spectrum was recorded between 10000 and 11400 cm–1 by a Fourier transform spectrometer with a spectral resolution of 0.05 cm–1. A multipass White-type cell with an optical path length of 24 m was used for the spectrum measurements. A light-emitting diode served as a radiation source, because it provides a higher brightness as compared to other emitters. A signal-to-noise ratio of 104 was gained for the strongest lines. During the D2О spectrum treatment, the experimental line list of about 100 lines of the ν1 + 3ν3 band was created. Spectroscopic parameters (line positions, intensities, and half widths) were calculated from fitting the experimental data to the Voigt line profiles by the least squares method. The analysis of the spectrum allowed us to derive new energy levels belonging to the vibrational state (103) of D216О.

Information system for molecular spectroscopy: 6—systematization of spectral data on deutero-substituted isotopologues of the hydrogen sulfide molecule

Properties of data published on the spectral line parameters for deutero-substituted isotopologues of the hydrogen sulfide molecule (HDS, HD34S, D2S, and D234S) are described. Most properties follow from the results of vacuum wavenumber quality analysis. Two applications used for the data quality analysis in W@DIS information system are described. The results of computer-based data quality analysis of vacuum wavenumbers are completed by the expert evaluation of the quality of the same data set. The rotation-vibrational transitions and energy levels of deutero-substituted isotopologues of the hydrogen sulfide molecule are imported into the database; their properties are collected in the knowledge base and available in the W@DIS information system (http://wadis.saga.iao.ru/).

LED-Based Fourier Transform Spectroscopy: the HD16O Absorption Spectrum in the Range of 11200–12400 cm−1

The vibrational—rotational spectrum of the HD16O molecule is studied within the range of 11200−12400 cm−1. The spectrum is recorded by an IFS-125M Fourier spectrometer with a resolution of 0.05 cm−1. The measurements are performed using a multipass White cell. A light-emitting diode is used as a radiation source. The signal-to-noise ratio was about 104. The centers, intensities, and half-widths of the spectral lines are determined by fitting to the experimental data by the least-squares method. A linelist containing more than 1500 lines is created. The results obtained are compared with the experimental data of other authors.

Study of the Water Vapor Absorption Spectrum in the Visible Spectral Region from 19480 to 20500 cm−1

The vibrational-rotational absorption spectrum of water vapor was recorded and analyzed in the visible spectral region from 19480 to 20500 cm−1. The measurements were carried out using an IFS-125M Fourier spectrometer with a resolution of 0.05 cm−1 at a pressure of 26.3 mbar, a temperature of (24 ± 1)°C, and optical path 24 m. We used a multipass White cell with a base length of 60 cm. A light-emitting diode was used as a radiation source. The signal-to-noise ratio was about 20000. The list of more than 420 lines has been compiled as a result of the analysis the spectrum, which includes line centers, intensities, and quantum vibrational-rotational numbers. More than 220 vibrational-rotational energy levels of 21 upper vibrational states have been determined from the experimental data.