Final atmospheric compositions of the planets shown in Fig. 1 of Paper II normalized to the solar composition. We also show the C/O ratio normalized to the solar value on the right of each panel, with Jupiter’s C/O ratio marked in gray (Atreya et al. 2016; Li et al. 2020), as well as the volatile-to-refractory ratio, which we calculate as the ratio of volatile to refractory molecules in the atmosphere. Left panels: models with 20% of the carbon abundance locked in refractory carbon grains, whereas right panels: models with 60% locked in carbon grains. The circles mark the composition of the pure atmosphere, while the triangles mark the composition if the core were completely mixed into the atmosphere.