code
petitRADTRANS:
Our group develops the opensource radiative transfer and retrieval package petitRADTRANS. The code’s documentation can be found here; the GitLab repository can be found here.
petitCODE:
petitCODE is a onedimensional code for calculating the structures as well as the emission and transmission spectra of planet atmospheres in radiativeconvective and chemical equilibrium. “petit” in petitCODE stands for “PressureTemperature Iterator and Spectral Emission and Transmission Calculator for Planetary Atmospheres”. At the moment petitCODE is not publically available. However, we are currentlty porting petitCODE to petitRADTRANS, to unify our tools into one opensource package.
petitCODE has been used to calculate the atmospheric models for clear and cloudy transiting and selfluminous planets, ranging in mass from superEarths to planets of multiple Jupiter masses. It has been used for spectral characterization, but also for planet evolutionary calculations.
Some of petitCODE's main properties are summarized below:
 petitCODE applies the 1d planeparallel approximation.
 Radiativeconvective equilibrium solutions.
 Selfconsistent treatment of scattering, emission, and absorption processes.
 Equilibrium chemistry, including equilibrium condensation.
 Molecular, atomic, and ion opacities for calculating planetary atmospheres from the coolest to ultrahot Jupiters, using hightemperature line lists where available.
 H_{2}H_{2} and H_{2}He collision induced absorption (CIA) and H^{} opacities.
 Cloud modeling, coupled selfconsistenly to atmospheric structure solution and radiative transport. Al_{2}O_{3}, H_{2}O (ice), Na_{2}S, KCl, Fe, MgSiO_{3}, Mg_{2}SiO_{4} and MgAl_{2}O_{4} clouds can be included.
 Correlatedk assumption for the line opacity treatment within the code.
 Calculation of angledependent, daysideaveraged or globally averaged emission spectra.
 Calculation of transmission spectra.
 Spectral resolutions of λ/Δλ = 10, 50, 1000 and 10^{6}.
petitCODE is a well tested and benchmarked code (see Baudino et al. 2017). Some examples for tests can be found below.

Comparison between correlatedk and linebyline calculations:
In order to test the reliability of the correlatedk implementation, the resulting planetary emission spectra were compared with spectra calculated at high resolution using a linebyline radiative transport scheme. The correlatedk calculations were carried out at a resolution R=λ/Δλ of 10, 50 and 1000. The linebyline calculation was carried out at a resolution of 10^{6} and was subsequently rebinned to the three correlatedk resolutions. The error between correlatedk and the linebyline calculation was in the low singledigit percentage range, usually at ~ 1 %.
A figure showing such a comparison calculation can be found here (taken from Mollière et al. 2015). 
Checking for flux conservation:
The radiation field arising from the converged solutions of the atmospheric structures fulfill flux conservation. At the top of the atmosphere the upwardmoving radiative flux is equal to the imposed insolation and internal flux. In the deeper layers of the atmosphere the upwarddirected radiative flux is equal to the imposed internal flux (the stellar flux has been absorbed in layers above). Finally, the radiative flux dwindles in the deepest regions because the atmosphere becomes convectively unstable and the flux is transported by convection. A figure showing an example calculation of the upwardmoving flux can be found here (taken from Mollière et al. 2015). 
Reproducing analytical solutions:
When enforcing the appropriate simplyfiying assumptions, petitCODE reproduces analytical solutions for planetary structures, such as the angledependent doublegray solutions from Guillot et al. (2010). A figure showing a comparison can be found here. The lines from left to right are pressuretemperature structures for insolation incidence angles of cos(θ) = 0.001, 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1. 
Scattering implementation:
When enforcing the appropriate simplyfiying assumptions, petitCODE scattering results perfectly agree with the predictions from Chandrasekhar's H functions. 
Benchmarking:
petitCODE has been succussfully benchmarked (see Baudino et al. 2017).