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The total internal partition sum, Qint(T), and the translational partition sum, Qtrans(T), were computed for six isotopologues of NO: 14N16O, 15N16O, 14N18O, 14N17O, 15N18O, 15N17O. These were used to determine the total partition sum, Q(T), and its first and second moments, Q ̃ ′ T and Q ̃ ″ T . The total internal partition sum was computed using term values determined by Qu et al. [Mon. Not. R. Astron. Soc. 504, 5768–5777 (2021)] for 14N16O and those of Wong et al. [Mon. Not. R. Astron. Soc. 470, 882–897, (2017)] for the other isotopologues. These term values are the best available and hence provide the most accurate total internal partition sums and its first and second moments. The uncertainties in Qint(T), its moments, and the resulting thermodynamic functions were determined from the uncertainty in the term values and the uncertainty due to the convergence of the partition sum and its moments. From these quantities, the isobaric heat capacity, Helmholtz energy, entropy, enthalpy, Gibbs function, and the JANAF functions hef and gef, and their uncertainties, were computed on a 1 K grid from 1 to 9000 K. The data are compared with the literature values. The resulting thermodynamic quantities are the most accurate determined from direct summation of Q(T), Q ̃ ′ T , and Q ̃ ″ T . [ABSTRACT FROM AUTHOR]

A series of spectra, one pure H2O and four H2O-O2 mixtures, were measured for the ν2 band in the 1200–1950 cm−1 region at room temperature using a single-pass copper cell housed in the Bruker 125HR high-resolution Fourier transform spectrometer (FTS) at Jet Propulsion Laboratory (JPL). All the five spectra were fit simultaneously using a multispectrum non-linear least-squares fitting software, Labfit programme suite, which adopts a speed-dependent Voigt line shape profile using full line mixing taken into account through a relaxation matrix operation. O2-broadened half-width and O2-induced frequency shift coefficients were determined for more than 350 transitions of H216O. These data were then checked using the smooth variation and paring rules [Brown et al. J Mol Spectrosc. 2007;246:1-21, Ma et al. Mol Phys. 2011;109:1925-41] and 186 transitions that obey the rules with less than 3% difference were chosen. Using these selected data, Modified Complex Robert-Bonamy calculations were made to determine the intermolecular potential for the H2O-O2 collision system. Some 93 potential were investigated resulting in a final potential (potential 74) that agrees with the selected half-width measurements having an average percent difference of 0.052 and a standard deviation of 5.108% between measurement and calculations. [ABSTRACT FROM AUTHOR]

New ExoMol line lists AloHa for aluminium hydride (AlH and AlD) are presented improving the previous line lists WYLLoT. The revision is motivated by the recent experimental measurements and astrophysical findings involving the highly excited rotational states of AlH in its A 1Π − X 1Σ+ system. A new high-resolution emission spectrum of 10 bands from the A 1Π − X 1Σ+ system of AlD, in the region 17 300–32 000 cm−1 was recorded with a Fourier transform spectrometer, which probes the predissociative A 1Π v  = 2 state. The AlD new line positions are combined with all available experimental data on AlH and AlD to construct a comprehensive set of empirical rovibronic energies of AlH and AlD covering the X 1Σ+ and A 1Π electronic states using the MARVEL approach. We then refine the spectroscopic model WYLLoT to our experimentally derived energies using the nuclear-motion code Duo and use this fit to produce improved line lists for 27AlH, 27AlD, and 26AlH with a better coverage of the rotationally excited states of A 1Π in the predissociative energy region. The lifetimes of the predissociative states are estimated and are included in the line list using the new ExoMol data structure, alongside the temperature-dependent continuum contribution to the photoabsorption spectra of AlH. The new line lists are shown to reproduce the experimental spectra of both AlH and AlD well, and to describe the AlH absorption in the recently reported Proxima Cen spectrum, including the strong predissociative line broadening. The line lists are included into the ExoMol data base www.exomol.com. [ABSTRACT FROM AUTHOR]

The total partition sum, Q(T), and its first and second moments, Q′(T) and Q″(T), were determined in terms of the total internal partition sum, Qint(T), and the translational partition sum, Qtrans(T), for 14N2, 14N15N, and 15N2. The total internal partition sum was computed using term values determined using the molecular constants of Le Roy et al. [J. Chem. Phys. 125, 164310 (2006)] for the ground electronic state and molecular constants for the first eight excited electronic states. The work of Le Roy et al. provides the best term values available and, hence, the most accurate total internal partition sums and their first and second moments. The convergence of Qint(T) and its moments were carefully studied and resulted in values with small uncertainty to 9000 K. From these quantities, the isobaric heat capacity, the Helmholtz energy, the entropy, the enthalpy, the Gibbs function, and the JANAF functions S0, hef, and gef, were computed on a 1 K grid from 1 to 9000 K. The resulting thermodynamic quantities are the most accurately determined from the direct summation of Q(T), Q′(T) and Q″(T). These data are compared with literature values. [ABSTRACT FROM AUTHOR]

Air-broadened half-widths of the 22- and 183-GHz water-vapor lines and associated uncertainties have been determined using comparisons between ground-based radiometric measurements from Atmospheric Radiation Measurement sites in Oklahoma and Alaska, and MonoRTM, a radiative transfer model. Values of the widths obtained using the measurements are 0.0900 [cm.sup.-1]/atm with 1.6% uncertainty for the 22-GHz line and 0.0992 [cm.sup.-1]/atm with 2.4% uncertainty for the 183-GHz line. Also presented are spectroscopic parameters for these lines from new calculations performed using the complex implementation of the Robert--Bonamy theory (CRB). The CRB values of the air-broadened widths are 0.0913 [cm.sup.-1]/atm with 3% uncertainty and a temperature exponent of 0.755 for the 22-GHz line and 0.0997 [cm.sup.-1]/atm with 3% uncertainty and a temperature exponent of 0.769 for the 183-GHz line. The values for the air-broadened half-widths derived from the measurement/model comparisons show good agreement with the new CRB calculations. For future versions of MonoRTM, width values of 0.0900 and 0.0997 [cm.sup.-1]/atm are to be adopted with temperature dependences of 0.76 and 0.77 for the 22- and 183-GHz lines, respectively. Index Terms--Microwave radiometry, satellite applications, water-vapor absorption, water-vapor retrieval.