Collisional data

They are mostly retrieved from the Leiden Lamda database. We also added data that are not in the Leiden database from the Basecol database.

Please cite in your papers as much as possible the recent (<5 yrs) original articles where the rates are measured or computed.

There are also special treatment for H2, H2O, OH, CO and CH+.

TODO: Update this or merge with heating cooling section, is rather confusing at the moment

See also the list of transitions available.

H2

  • Rovibrational level energy, degeneracy and rates with H are from "The rovibrational excitation of H2 induced by H" S.A. Wrathmall, D.R. Flower, 2007, J. Phys. B: At. Mol. Opt. Phys. 40 3221-3230
  • Einstein A coefficients from Wolniewicz, Simbotin & Dalgarno 1998 ApJ 115, 293, "Quadrupole transition probabilities for the excited rovibrational state of H2 in the ground electronic level
  • Electronic level from Abgrall et al. 2000, A&AS, 141, 297-300
  • H2-He, H2-pH2, and H2-oH2 from Le Bourlot J., Pineau des Forets G., Flower D. R., 1999, MNRAS, 305, 802

see H2 UV for details on the UV fluorescence option.

TODO: Are there other (undocumented) options for H2?

H2O

Has various options see H2O_rovibrational_cooling for details. The data are taken from:

  • The Leiden Lamda database H2O
  • Levels, degeneracies, and Einstein coefficients from the HITRAN database
  • Collision rates from Faure et al. 2008 A&A 492,257 and Faure et al. 2007 A&A 472, 1029F
  • Daniel et al. (2011, A&A, 536, A76) rates with H2 can be used for the rotational levels instead of the Faure et al. 2007 rates. You need to check the option

OH

We expanded the Leiden-Lamda collisional data for OH(version before Dec. 25) with normal-H2\rm{H}_2 to higher level transitions and higher temperatures. The merging of the o-H2\rm{H}_2 and p-H2\rm{H}_2 collision rates from Lamda into normal-H2\rm{H}_2 assumes a fixed H2\rm{H}_2 ortho-to-para ratio of 3/1. The spectroscopic data are taken from the ExoMol database. The hyperfine splitting is not accounted for.

The expansion to higher levels follow the method described in Tabone et al. 2021.

The expansion in temperature uses a simple exponential law of index 0. (i.e. square root). The total vibrational collisional rates (i.e. within two vibrational levels considering all the rotational levels) are taken from: U. Rahmann, W. Kreutner, K. Kohse-Höinghaus+ (1999). The same paper provides the equal probability methods to expand the total vibrational rates to ro-vibrational rates.

We also include a more recent (Dec. 2025) Lamda file for OH (OH_zeno_Lambda.dat) without modifications. See Custom Molecules/lines for how to use this file.

For the default setup and other options see OH cooling.

Spectroscopic databases

They are sometimes used in ProDiMo when the data are not available in the Lamda database

CHIANTI database

Atomic spectroscopic and collision rates with electrons (based on the Opacity and Iron projects) can be found in the CHIANTI database

ProDiMo can read spectroscopic data in the CHIANTI database format http://www.chiantidatabase.org/.

Special cases

  • CH+, see Thi et al. 2011 paper on CH+ for a list of physico-chemistry papers