  Molecular features such as the G-band, CN-band and NH-band are important
diagnostics for measuring a star's carbon and nitrogen abundances, especially
in metal-poor stars where atomic lines are no longer visible in stellar
spectra. Unlike atomic transitions, molecular features tend to form in bands,
which cover large wavelength regions in a spectrum. While it is a trivial
matter to compute carbon and nitrogen molecular bands under the assumption of
1D, it is extremely time consuming in 3D. In this contribution to the 2016
CO5BOLD workshop we review the improvements made to the 3D spectral synthesis
code Linfor3D, and discuss the new challenges found when computing molecular
features in 3D.
