The high resolution IR spectral data of isotopologues are important in both atmospheric and astronomical studies. We report semi-empirical IR line lists for isotopologues of both Carbon Dioxide and Sulfur Dioxide, which are the most complete, consistent lists and highly accurate. It follows the �Best Theory + Reliable High-resolution Experimental Data� strategy, i.e. using reliable experimental data to empirically refine the most accurate ab initiopotential energy surfaces (PES) and running rovibrational calculations on the refined PES together with pure ab initio dipole moment surfaces (DMS) to get IR transition frequencies and intensities.For SO2, we used selected 32S16O2 HITRAN data instead of experimentally measured data during the PES refinement. The root-mean-squares error (sRMS) for all 32S16O2 J=0-80 rovibrational energy levels computed on the refined PES (denoted Ames-1) is 0.013 cm-1. With a CCSD(T)/aug-cc-pV(Q+d)Z dipole moment surface (DMS), an infrared (IR) line list (denoted Ames-296K) has been computed at 296K and covers E' < 8,000 cm-1.[Huang et al. JCP 2014 (in press)] We will present IR lists of five symmetric isotopologues (626, 636, 646, 666, and 828), where the band origins below 5500 cm-1 should be accurate to uncertainty of 0.01-0.03 cm-1. In addition, we discuss the intensity agreement, line position deviation at high Ka, predictive accuracy for isotopologues and higher energies, as well as the discrepancies and possible fixes.For CO2, a purely experimental dataset was used in the PES refinement which led to sRMS = 0.0156 cm-1 for 6873 J=0-117 rovibrational levels up to 13,000 cm-1.[Huang et al, JCP 136, 124311 (2012)] After reporting 12C16O2 IR line lists for T up to 1000 � 1500K and E' < 24,000 cm-1,[Huang et al, JQSRT 130, 134 (2013).] we have computed J=0-150 IR line lists for the other 12 isotopologues of Carbon Dioxide: 636, 628, 627, 828, 727, 827, 638, 637, 737, 838, 738, and 646.[Huang et al, JCP 2014, submitted] Line shape parameters including temperature dependence are calculated and reported for four temperature ranges: Mars (150-296K), Earth (200�350 K), Venus (296-700 K), and Hotter (700 � 2000K). Line position accuracy for most transitions up to 10,000 cm-1 � 13, 000 cm-1 is better than 0.03-0.05 cm-1. Computed transition intensities agree well with most HITRAN data but there exist suspicious exceptions for some isotopologues.These line lists will greatly facilitate SO2 and CO2 IR spectral experimental analysis, eliminate related spectral lines in high-resolution astronomical observations, and provide the scientific community with trustworthy alternatives for unknown IR bands. Mass-dependent correction terms and nonadiabatic corrections were excluded from the current SO2 and CO2 studies, but may be added in future studies.

Accurate infrared line lists computed for CO<sub>2</sub> and SO<sub>2</sub> isotopologues

248th National Meeting (2014)

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Accurate infrared line lists computed for CO2 and SO2 isotopologues

Accurate infrared line lists computed for CO₂ and SO₂ isotopologues