HELIOS, a radiative transfer code, is constructed for studying exoplanetary atmospheres. The model atmospheres of HELIOS are one-dimensional and plane-parallel, and the equation of radiative transfer is solved in the two-stream approximation with non-isotropic scattering. Though HELIOS can be used alone, the opacity calculator HELIOS-K (ascl:1503.004) can be used with it to provide the molecular opacities.
https://ui.adsabs.harvard.edu/abs/2017AJ....153...56M and https://ui.adsabs.harvard.edu/abs/2019AJ....157..170M ; please see additional information here: https://github.com/exoclime/HELIOS