HITRAN

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 can be recreated or updated with the python code:

python3 hitran2.py

The file format is:

Species ID, Abundance, Molecular Mass in g/mol, Q(296K), partition function file, gi, Isotopologue Formula

The same information can be found at https://hitran.org/docs/iso-meta/.

The species ID consists 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 combined, e.g. 01_1 for 1H2-16O or 01 for all isotopogolues from H20.

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. It is important to use this naming convention, otherwise the following steps will not work properly.

Example for water (molecule id = 01) and a choose line list name = hit16 (for Hitran 2016):

01_hit16.par

Download also all the necessary partition function files from www.hitran.org under 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.

Example for water (molecule id = 01), isotopolgue = 1 and a choose line list name = hit16:

./hitran -M 1 -ISO 1 -in hit16

This example will produce the species parameter file 01_1_hit16.param and the binary line list file called 01_1_hit16.bin.

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.