Calculate a spectrum from ExoMol

Auto-download and compute a SiO spectrum from the ExoMol database ([ExoMol-2020])

from radis import calc_spectrum

s = calc_spectrum(
    1080,
    1320,  # cm-1
    molecule="SiO",
    isotope="1",
    pressure=1.01325,  # bar
    Tgas=1000,  # K
    mole_fraction=0.1,
    path_length=1,  # cm
    databank=("exomol", "EBJT"),  # Simply use 'exomol' for the recommended database
)
s.apply_slit(1, "cm-1")  # simulate an experimental slit
s.plot("radiance")
plot exomol spectrum
========== Loading Exomol database [start] ==========
                 => Downloading from http://www.exomol.com/db/SiO/28Si-16O/EBJT/28Si-16O__EBJT.def
                 => Downloading from http://www.exomol.com/db/SiO/28Si-16O/EBJT/28Si-16O__EBJT.pf
                 => Downloading from http://www.exomol.com/db/SiO/28Si-16O/EBJT/28Si-16O__EBJT.states.bz2
                 => Downloading from http://www.exomol.com/db/SiO/28Si-16O/28Si-16O__H2.broad
                 => Downloading from http://www.exomol.com/db/SiO/28Si-16O/28Si-16O__He.broad
                 => Downloading from http://www.exomol.com/db/SiO/28Si-16O/28Si-16O__air.broad
Error: Couldn't download .broad file at http://www.exomol.com/db/SiO/28Si-16O/28Si-16O__air.broad and save.
Note: Caching states data to the vaex format. After the second time, it will become much faster.
Molecule:  SiO
Isotopologue:  28Si-16O
Background atmosphere:  Air
ExoMol database:  EBJT
Local folder:  /home/docs/.radisdb/exomol/SiO/28Si-16O/EBJT
Transition files:
         => File 28Si-16O__EBJT.trans
                 => Downloading from http://www.exomol.com/db/SiO/28Si-16O/EBJT/28Si-16O__EBJT.trans.bz2
                 => Caching the *.trans.bz2 file to the vaex (*.h5) format. After the second time, it will become much faster.
                 => You can deleted the 'trans.bz2' file by hand.
/home/docs/checkouts/readthedocs.org/user_builds/radis/checkouts/latest/radis/api/exomolapi.py:1257: UserWarning:

Could not load `28Si-16O__Air.broad`. The default broadening parameters are used.


========== Loading Exomol database [end] ==========

/home/docs/checkouts/readthedocs.org/user_builds/radis/checkouts/latest/radis/misc/warning.py:427: MissingPressureShiftWarning:

Pressure-shift coefficient not given in database: assumed 0 pressure shift

Calculating Equilibrium Spectrum
Physical Conditions
----------------------------------------
   Tgas                 1000 K
   Trot                 1000 K
   Tvib                 1000 K
   isotope              1
   mole_fraction        0.1
   molecule             SiO
   overpopulation       None
   path_length          1 cm
   pressure             1.01325 bar
   rot_distribution     boltzmann
   self_absorption      True
   state                X
   vib_distribution     boltzmann
   wavenum_max          1320.0000 cm-1
   wavenum_min          1080.0000 cm-1
Computation Parameters
----------------------------------------
   Tref                 296 K
   add_at_used          cython
   broadening_method    voigt
   cutoff               1e-27 cm-1/(#.cm-2)
   dbformat             exomol-radisdb
   dbpath               /home/docs/.radisdb/exomol/SiO/28Si-16O/EBJT
   folding_thresh       1e-06
   include_neighbouring_lines  True
   memory_mapping_engine  auto
   neighbour_lines      0 cm-1
   optimization         simple
   parfuncfmt           exomol
   parsum_mode          full summation
   pseudo_continuum_threshold  0
   sparse_ldm           True
   truncation           50 cm-1
   waveunit             cm-1
   wstep                0.01 cm-1
   zero_padding         24001
----------------------------------------
0.04s - Spectrum calculated

<matplotlib.lines.Line2D object at 0x7f705d379850>
"""ExoMol lines can be downloaded and accessed separately using
:py:func:`~radis.io.exomol.fetch_exomol`
"""

# See line data:
from radis.io.exomol import fetch_exomol

df = fetch_exomol("SiO", database="EBJT", isotope="1", load_wavenum_max=5000)
print(df)
========== Loading Exomol database [start] ==========
                 => Downloading from http://www.exomol.com/db/SiO/28Si-16O/28Si-16O__H2.broad
                 => Downloading from http://www.exomol.com/db/SiO/28Si-16O/28Si-16O__He.broad
                 => Downloading from http://www.exomol.com/db/SiO/28Si-16O/28Si-16O__air.broad
Error: Couldn't download .broad file at http://www.exomol.com/db/SiO/28Si-16O/28Si-16O__air.broad and save.
Molecule:  SiO
Isotopologue:  28Si-16O
Background atmosphere:  Air
ExoMol database:  EBJT
Local folder:  /home/docs/.radisdb/exomol/SiO/28Si-16O/EBJT
Transition files:
         => File 28Si-16O__EBJT.trans
/home/docs/checkouts/readthedocs.org/user_builds/radis/checkouts/latest/radis/api/exomolapi.py:1257: UserWarning:

Could not load `28Si-16O__Air.broad`. The default broadening parameters are used.


========== Loading Exomol database [end] ==========

        i_upper  i_lower             A  ...            int  airbrd  Tdpair
0         24300    24299  1.926600e-12  ...  3.923990e-167    0.07     0.5
1          4698     5073  3.431600e-10  ...  2.626438e-202    0.07     0.5
2         24273    24272  1.652000e-10  ...  2.386983e-165    0.07     0.5
3         24301    24300  1.725200e-11  ...  2.947629e-166    0.07     0.5
4         24232    24231  7.675700e-10  ...  1.291448e-164    0.07     0.5
...         ...      ...           ...  ...            ...     ...     ...
249599     3769     1818  2.429700e-04  ...   3.947150e-91    0.07     0.5
249600     8052     6269  1.481800e-02  ...   2.484685e-72    0.07     0.5
249601     8693     6938  1.601100e-02  ...   1.337757e-67    0.07     0.5
249602     8659     6904  1.166600e-02  ...   3.267363e-66    0.07     0.5
249603     7665     5871  3.160000e-03  ...   4.399687e-64    0.07     0.5

[249604 rows x 11 columns]

See the list of recommended databases for the 1st isotope of SiO :

from radis.io.exomol import get_exomol_database_list, get_exomol_full_isotope_name

databases, recommended = get_exomol_database_list(
    "SiO", get_exomol_full_isotope_name("SiO", 1)
)
print("Databases for SiO: ", databases)
print("Database recommended by ExoMol: ", recommended)
Databases for SiO:  ['Kurucz-SiO', 'EBJT', 'xsec-SiOUVenIR', 'SiOUVenIR']
Database recommended by ExoMol:  SiOUVenIR

Total running time of the script: (0 minutes 9.924 seconds)