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The current report covers the period from the second half of 2011 to late 2014. It is divided into three areas covering rotational, vibrational, and electronic spectroscopy. A signifcant amount of experimental and theoretical work has been accomplished over the past three years, leading to the development and expansion of a number of databases whose links are provided below. Two notable publications have appeared recently: An issue of The Journal of Physical Chemistry A in 2013 honoring the many contributions of Takeshi Oka (J. Phys. Chem. A, 117, pp. 9305-10143); and IAU Symposium 297 on Diffuse Interstellar Bands. A number of the relevant papers from these volumes are cited. Related research on collisions, reactions on grain surfaces, and astrochemistry are not included here., Comment: TRIENNIAL REPORT 2012-2015, 16 pages, to be published in Transactions IAU, Volume 29A, Reports on Astronomy 2012-2015, Thierry Montmerle, ed

A new line list including positions and absolute intensities (in the form of Einstein $A$ values and oscillator strengths) has been produced for the OH ground X\DP\ state rovibrational (Meinel system) and pure rotational transitions. All possible transitions are included with v$\primed$ and v$\Dprimed$ up to 13, and $J$ up to between 9.5 and 59.5, depending on the band. An updated fit to determine molecular constants has been performed, which includes some new rotational data and a simultaneous fitting of all molecular constants. The absolute line intensities are based on a new dipole moment function, which is a combination of two high level ab initio calculations. The calculations show good agreement with an experimental v=1 lifetime, experimental $��_\mathrm{v}$ values, and $��$v=2 line intensity ratios from an observed spectrum. To achieve this good agreement, an alteration in the method of converting matrix elements from Hund's case (b) to (a) was made. Partitions sums have been calculated using the new energy levels, for the temperature range 5-6000 K, which extends the previously available (in HITRAN) 70-3000 K range. The resulting absolute intensities have been used to calculate O abundances in the Sun, Arcturus, and two red giants in the Galactic open and globular clusters M67 and M71. Literature data based mainly on [O I] lines are available for the Sun and Arcturus, and excellent agreement is found., 17 pages, 8 figues. 7 supplementary files: dipole moment functions (OH-X-DMFs.txt), equilibrium constants (OH-X-Equilibrium_Constants.txt), partition function (OH-X-Q_5-6000K.dat), PGOPHER file with molecular constants and transition matric elements (OH-XX.pgo), vibrational Einstein A and f values (OH-XX-Avv_fvv.txt), line list (OH-XX-Line_list.txt), and OH-Transformation_Equation_Extra.docx

The results of an IUPAC Task Group formed in 2004 on “A Database of Water Transitions from Experiment and Theory” (Project No. 2004-035-1-100) are presented. Energy levels and recommended labels involving exact and approximate quantum numbers for the main isotopologues of water in the gas phase, H216O, H218O, H217O, HD16O, HD18O, HD17O, D216O, D218O, and D217O, are determined from measured transition wavenumbers. The transition wavenumbers and energy levels are validated using the MARVEL (measured active rotational–vibrational energy levels) approach and first-principles nuclear motion computations. The extensive data, e.g., more than 200,000 transitions have been handled for H216O, including lines and levels that are required for analysis and synthesis of spectra, thermochemical applications, the construction of theoretical models, and the removal of spectral contamination by ubiquitous water lines. These datasets can also be used to assess where measurements are lacking for each isotopologue and to provide accurate frequencies for many yet-to-be measured transitions. The lack of high-quality frequency calibration standards in the near infrared is identified as an issue that has hindered the determination of high-accuracy energy levels at higher frequencies. The generation of spectra using the MARVEL energy levels combined with transition intensities computed using high accuracy ab initio dipole moment surfaces are discussed.