Step 1, Species Properties

The HELIOS-K repository provides a file called Hitran_species.dat. This file contains all available species of the Hitran database. The file format is:

Species ID, Abundance, Molecular Mass, Q(296K), partition function file, Isotopologue Formula The same information can be found at https://hitran.org/docs/iso-meta/.

The species ID consitst of a two digits molecule ID and a one digit local isotopologue ID. Note that the local isotogologue ID can sometimes consist of non numerical values. e.g A or B,

For identifying a species, the molecule number and the isotopologue number should be combinded, e.g. 01_1 for 1H2-16O or 01 for all isotopogolues from H20.

The Hitran_species.dat file can be recreated or updated with the python code hitran2.py.

Step 2, Download the files

The line list files must be downloaded manually from www.hitran.org`, and note that it is necessary to register on the hitran homepage. To download the files, select DataAcess and then Line-by-line. Select the molecule id, select all isotopologues (single isotopologues can be filtered later), leave wavenumber range blank, select .parfile and store the file on your computer under the name Molecule-ID_hit16.par, e.g. 01_hit16.par for H2O.

Download all the necessary partition function files from Documentation/Isotogologues.

Step 3, create <species_name>.param file and the binary files

All necessary files can be created with:

./hitran -M < molecule ID > -ISO < isotopologue ID > -in < line list name >

The <molecule ID> is the two digit molecule number, e.g. 01 for H2O. The <isotopologue ID> is the hitran internal isotopologue identifier, e.g. 1 for 1H2-16O. The <line list name> is the name that was given in the download section, e.g. hit16.

Step 4, data path

Include the path of the directory, which contains the obtained binary files, the *.txt partition function files and the *.param file to the HELIOS-K param.dat file under pathToData.