Custom Lines/Molecules

It is also possible to include line data in the HITRAN or LAMDA format that are not included in ProDiMo, as so called custom species/molecules.The number of extra species is limited to 10 molecules per run (i.e., can only include ten 'custom molecule' at any one time).

This is a quite convenient way to e.g. use a new data file that is no yet include in the ProDiMo source distribution, or to compare two different line data files.

To include those custom species, one needs to define them in the LineSelection.in file. The following shows an example to include a HITRAN and an additional LAMDA species.

***********************************************************
******** Input file for line selection with ProDiMo *******
***********************************************************

*** Example for a HITRAN molecule ***
C2H6_C      ! custom_molecule
1           ! iso
30          ! mass
1           ! waveSelection
4 30 
1           ! ESelection
0 30000 
1e-20       ! hitran_min_strength
'/path/to/file/C2H6.par' ! file
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*** Example for a LAMDA molecule ***
HCN-hfs_C       ! custom_molecule   : name of the SYS, _C required for custom molecule
LAMDA           ! type              : is it a LAMDA molecule ?
HCN             ! cspname           : name of the associated chemical species
.false.         ! coolant           : include it in the heating/cooling balance? (true/false)
"./hcn@hfs.dat" ! file              : the filename of the LAMDA file "./" means look in the current (model) directory. 
-------------------------------------------------------

The first switch custom_molecule tells ProDiMo that the line species is a custom molecule. The name of the species has to end with _C to be recognised as a custom molecule.

For the HITRAN case (C2H6_C in the example), one has to include isotopologue number, molar mass, waveSelection, ESelection, hitran_min_strength. These are the required line selection rules. For details see Mid-IR Lines. The last parameter file is the path to the line data file, which in that case has to be in the HITRAN format. In the example above an absolute path is used. If the file name starts with ./ or ../ then it is a relative path (relative to the working/model directory). Without any prefix (e.g. just "C2H6.par"), ProDiMo will look in the ProDiMo_datapath directory for the file.

By this custom molecule line selection, one can produce models for existing HITRAN ProDiMo molecules by defining them as custom and then using required isotopologue number; e.g. 2 ! iso. A custom molecule and its isotopologues can be defined as two independent species by using _C for the main molecule name and _I_C for the isotopologue; and 1 ! iso and 2 ! iso for isotopologue numbers. However, this still limits to using two isotopologues of a molecule in a run.

ProDiMo provides some additional custom line data files in the HITRAN format which can be directly used as custom molecules, see List of transitions.

For the LAMDA case (HCN-hfs_C in the example file), one needs to include the type of the species (LAMDA), the name of the associated chemical species (which has to be in the Species.in file), whether it is included in the heating/cooling balance, and the path to the line data file (which has to be in the LAMDA format). The example above shows a relative path, which means that ProDiMo will look for the file in the current model directory. If one wants to limit the maximum number of energy levels considered, one can add the switch NlevMax and the maximum number of levels to be included (e.g., 20 ! NlevMax). This option is only relevant for LAMDA species.

More examples of LineSelection.in can be found in the directories

  • prodimo/examples/Processes/CustomHITRAN_CH3+
  • prodimo/examples/Processes/CustomHITRAN_ExoMol