The GEISA 2020 sub-database on line transition parameters

The GEISA 2020 sub-database of line transition parameters involves 58 molecules (145 isotopic species) and contains 6,746,982 entries, in the spectral range from 10-6 to 35,877.030506 cm-1.


The GEISA molecules are constituents of the atmospheres of Earth (major permanent and trace molecules) and of other Planets (such as: C2H4, GeH4, C3H8, C2N2, C4H2, HC3N, H2S, HCOOH and C3H4/H2C3H2, for the Giant Planets).

In this version, 20 molecules have been updated (with 12 new isotopic species) and 6 new molecules have been added (HONO, COFCl, CH3F, CH3I, RuO4, H2C3H2 (isomer of C3H4)) corresponding to 15 isotopic species.



Among the 31 spectroscopic parameters archived in GEISA, the most important for atmospheric radiative transfer modelling are: the wavenumber (cm-1) of the line associated with a vibro-rotational transition, the intensity of the line (cm molecule-1 at 296K), the Lorentzian collision halfwidth (cm-1 atm-1 at 296 K), with associated self – pressure broadening parameter, the energy of the lower level of the transition (cm-1), the transition quantum identifications for the lower and upper levels of the transition, the temperature dependence coefficient of the halfwidth, the database management identification codes for isotopologues and for molecules.