Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5428622 | Journal of Quantitative Spectroscopy and Radiative Transfer | 2013 | 13 Pages |
â¢Theoretical IR line lists for IR simulations up to 1000-1500 K.â¢Updated CCSD(T)/aug-cc-pVQZ dipole moment surface is used.â¢First line lists reliably covering up to 18,000-23,000 cmâ1.â¢Recent experiments confirmed Ames 5001r-00001 intensities.â¢Compare to HITEMP and recent experiments up to 1773 K.
New semi-empirical Infrared (IR) line lists for 12C16O2, Ames-296 K and Ames-1000 K, have been computed using a newly updated ab initio CCSD(T)/aug-cc-pVQZ dipole moment surface (denoted DMS-N2) and an empirically refined potential energy surface (Ames-1). J=0-150 rovibrational levels are computed up to 30,000 cmâ1, and related transitions are cut off at 1Eâ42 cm moleculeâ1 (296 K) and 1Eâ36 cm moleculeâ1 (1000 K). These are the first line lists available to cover reliably the energy region as high as ~20,000 cmâ1. Recent experimental data at 1.1 μm has confirmed the predicted intensities for the 50013-00001 and 50014-00001 band transitions have better than 90% agreement. Comparisons are made against the Wattson 750 K line list and HITEMP/HITRAN at 300 K, 500 K, 725 K, 1000 K, 1500 K, 2000 K and 3000 K. The temperature dependence and accuracy of the new Ames-296 K/1000 K line lists are investigated and we claim both line lists are capable of providing reliable opacities up to 18,000-23,000 cmâ1, while the highest applicable wavenumber range drops as T rises. We suggest caution is used for T>1000 K simulations. Comparison to recent experiments at 1000 K, 1550 K and 1773 K shows that the Ames-1000 K line list and HITEMP perform similarly in the 3200-3800 cmâ1 and 4600-5200 cmâ1 ranges. In the 2000-2100 cmâ1 range, Ames-1000 K yields better agreement relative to experiment. Existing problems and possible future solutions in the new Ames-296 K/1000 K line lists for line positions and intensities are also discussed.