If you have access to the hulk cluster at the University of Bern, then most of the pre-processed files are already available at scratch/sigrimm/EXOMOL/. This files can then directly be used for the opacity calculation.

## Supported line list databases¶

HELIOS-K supports line lists from the HITRAN, HITEMP, ExoMol, Kurucz, NIST or VALD databases. Before the line lists can be used, they have to be pre-processed into binary files. This saves in generally memory space and allows HELIOS-K to read the line lists in a more efficient way.

The next section explains the structure of these files and shows how to generate them.

## The <species_name>.param file¶

Each molecular or atomic species, which will be processed by HELIOS-K, needs a <species_name>.param file, which contains all necessary information about the line list database and other parameters. This files can be generated automatically by the tools in HELIOS-K. However, when using a different database, they must be created manually.

## Example¶

An example for HITRAN 2016 H2O is given in the data/01_hit16.param file, which is shown here and available in the repository. An example for HITEMP and ExoMol are also given in the repository files data/01_HITEMP2010.param and data/1H2-16O__BT2.param.

01_hit16.param
-------------------------------------------------------------------
Database = 0
Molecule number = 1
Name = hit16
Number of Isotopologues = 7
#ID Abundance      Q(296K)   g     Molar Mass(g)  partition file :
11 0.997317        174.58    1     18.010565      q1.txt
12 0.002000        176.05    1     20.014811      q2.txt
13 3.718840E-04    1052.14   6     19.01478       q3.txt
14 3.106930E-04    864.74    6     19.01674       q4.txt
15 6.230030E-07    875.57    6     21.020985      q5.txt
16 1.158530E-07    5226.79   36    20.020956      q6.txt
17 2.419700E-07    1027.80   1     20.022915      q129.txt
Number of columns in partition File = 2
Number of line/transition files = 1
Number of lines per file :
304225
Line file limits :
0
30000
#ExoMol :
Number of states = 0
Number of columns in transition files = 0
Default value of Lorentzian half-width for all lines = 0
Default value of temperature exponent for all lines = 0
Version = 0
-------------------------------------------------------------------


## Arguments¶

• Database: Indicate which database format to use.

• 0 = Hitran or HITEMP

• 2 = ExoMol

• 30 = Kurucz atomic database

• 31 = NIST atomic database

• Molecule number: This is optional and follows an old HELIOS-K version.

• Name: name of the line list files.

• Number of isotopologues in the line list files.

• For each isotopologue:

• ID: for Hitran and HITEMP the same as the first three digits in the *.par files e.g. 11 for 1H2-18O, or 2A for 18O-13C-17O. For ExoMol no meaning.

• Abundance, only relevant for more than one isotopologue.

• Reference partition function value. For ExoMol no meaning.

• Molar mass in g.

• Name of the partition function file.

• Number of columns in the partition function file.

• Number of line/transition files.

• Line by line, the number of molecular/atomic lines in each line/transition file.

• Line by line, the wavenumber range of each line/transition file, must have one entry more than the number of line/transition files to cover all lower and upper range limits.

• Number of states in ExoMol *.statesfiles. For other databases no meaning.

• Number of columns in ExoMol *.transfiles. For other databases no meaning.

• ExoMol default value of Lorentzian half-width. For other databases no meaning.

• ExoMol default value of temperature exponent. For other databases no meaning.

• Version of the line list.