Best-fitting slab models of ¹²CO₂, HCN, and C₂H₂ in the 13.6–16.3 µm wavelength region. The top panel displays the continuum subtracted JWST spectrum in a specific region, while the full model spectrum is shown in red. In addition, the horizontal bars show for each molecule the spectral windows used in the χ² fits. The bottom panel shows the models for the individually detected molecules. The H₂O and OH slab models are shown for completeness. Their model properties will be presented in Temmink et al. (in prep.)