ExoMol super-lines

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 super line files can be downloaded with the a python script as:

python3 exomol.py -M <id> -D 3 -Temp <T>

where <id> is the full species name e.g. 1H2-16O__POKAZATEL. The -D 3 specifies to download the super-lines instead of the full transition and states files. The <T> specifies the temperature of the super lines in K, e.g. -Temp 1000. When multiple temperatures are needed, the each temperature file must be downloaded and processed individually.

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:

./prepareExomolSuper -M < id >

where < id > is the full super-line file name, e.g. 1H2-16O__POKAZATEL__00000-41200__1000K_super.. After this step, the *.super 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.

Running HELIOS-K

When running HELIOS-K, the temperature of the calculation must corespond to the temparture of the super-lines. Otherwise the result is not not correct.

Fig. 1 Comparison of the full POKAZATEL 1H2-16O opacity and super-lines for 1000 K. The voigt profiles are truncated at 100 cm^-1.