Data available to downloadSince November 2017 the structure of the “Molecules” section is slightly modified. In general, three types of data could be made available for an isotopologue of an included molecule.
- Full line-by-line (LbL) linelists at low and/or room
reference temperatures without quantum identification of the transition (“full_LbL_lists”). The cut-off restrictions ( described case-by-case) permit to employ these “full_LbL_lists” within the temperatures range ( Tmin , Tmax) specified for each molecule, by an appropriate use of the T-dependence for intensities and for the partition functions.
- “Hybrid” compressed data sources designed for a fast spectra modeling.
For heavy molecules with low vibrational frequencies as well as for light molecules at high temperatures, the spectra could be very congested including many millions or even billions of transitions ( see refs , ). To accelerate a modeling of spectral functions in these cases the initially computed full LbL lists are partitioned into two sets:
(b1) “Light lists” contain strong and medium transitions necessary for an accurate description of sharp features in absorption/emission spectra.
(b2) For a fast and efficient modeling of quasi-continuum cross sections, billions of tiny lines are compressed in “super-lines” libraries according to ref .
Warning (!) : For a correct use of these “hybrid” data sources, the spectral functions computed from (b1) “Light lists” and from (b2) “quasi-continuum” must be summed together. Otherwise , a part of the opacity would be missing.
- Linelists at various reference temperatures with full quantum identification of the transition (Assigned linelists) : currently few limited examples – under development.
References ( compression methods)
- Rey, M., Nikitin, A.V., Tyuterev, V.G. “Theoretical hot methane line lists up to t = 2000 k for astrophysical applications”. Astrophysical Journal, 789 (1), art. no. 2, (2014); doi: 10.1088/0004-637X/789/1/2.
- Rey, M., Nikitin, A.V., Tyuterev, V.G. “Accurate Theoretical Methane Line Lists in the Infrared up to 3000 K and Quasi-continuum Absorption/Emission Modeling for Astrophysical Applications”. Astrophysical Journal, 847 (2), art. no. aa8909 (2017); doi: 10.3847/1538-4357/aa8909.
- M. Rey, A.V. Nikitin, Y. Babikov, V. Tyuterev, TheoReTS - An information system for theoretical spectra based on variational predictions from molecular potential energy and dipole moment surfaces // JMS, 2016, doi:10.1016/j.jms.2016.04.006.
References on ab initio surfaces and methods of spectra calculations are given in sections corresponding to included molecules
( see also list of "Original References " in the main menu )