Example model from the population synthesis set at t_max. The x-axis of each panel spans approximately 0.3 pc, or 350” assuming a cloud distant 170 pc from the observer. For the sake of clarity, this plot shows a smaller inner region of the actual computational domain. Upper left panel: Total number density radial profile (blue curve, left y-scale), cosmic-ray ionization rate ζ (orange, right y-scale). Upper right: Gas (orange) and dust (blue) temperature radial profiles (both on left y-scale), and radial velocity profile (green, right y-scale). Lower left: Cooling and heating contributions. In particular, Λ_d is the dust cooling, Λ_CO the CO cooling, Λ_Z the cooling from atomic species (C, C⁺, and O); instead, Γ_ad is the adiabatic heating (i.e., compressional heating), Γ_CR the cosmic-ray heating, and Γ_phe the dust photoelectric heating. The cooling and heating contributions below 10⁻²⁶ erg s⁻¹ cm⁻³ are not reported in the legend. Lower right: Radial profile of a subset of the chemical species computed with the network of 4406 reactions. The fractional abundance is relative to the total number density. CO_d (dashed green) is the CO on the dust surface. The comparison with Sipilä & Caselli (2018) is reported in Appendix C.