Performance of ML-accelerated chemistry predictions for CO. (a): mean log₁₀ predicted relative abundance as a function of local temperature, gas density, and ionization rate. Darker areas correspond to larger relative (to H atoms) abundance. (b): median of the difference between the predicted values and test set data (bias, dex), in dex, as a function of temperature and density. Gray areas correspond to an unbiased fit. (c): the standard deviation between the predicted values and test set data, in dex (std, dex). (d): relative density (histogram) of species within the data points, with contours, which are also present on other panels. Various regions of the protoplanetary disk are described on panel (a). A detailed description of the processes leading to this figure is in the main text. Other molecules are shown in Fig. A.1.