# ExoMol¶

## Step 1, Species Properties¶

The HELIOS-K repository provides a file called Exomol_species.dat. This file contains all available species from the ExoMol database. The file format is:

Molecule name , Isotopologue name, Full name, path on exomol.com, range of *.trans files, number of *.trans files, number of digits in *.trans file ranges.

The full name of the species contains the isotopologue and the line list name. This full name should be used when as species name for the opacity calculation, e.g. 1H2-16O__BT2.

The Exomol_species.dat file can be recreated or updated by running:

python3 exomol2.py


## Step 2, Download the files and create the <species_name>.param file¶

The ExoMol files can be downloaded with the a python script as:

python3 exomol.py -M <id>


where <id> is the full species name e.g. 1H2-16O__BT2. The script needs the file Exomol_species.dat to be availalbe. If this file needs to be updated, it can be done by running python3 exomol2.py.

The exomol.py script automatically writes the <species_name>.param files for each molecule.

## Step 3, create the binary files¶

The downloaded line list files must be pre-processed into binary files with the following code:

./prepareExomol -M < id >


where < id > is the full species name, e.g. 1H2-16O__BT2. After this step, the *.trans and *.states files from ExoMol can be deleted.

## Step 4, data path¶

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