Time-dependent abundances as computed with the Heidelberg (crosses) and Bordeaux (solid line) chemical models for the “TMC1” case. The X-axes show time in years. The Y-axes are abundances relative to the total amount of hydrogen nuclei. The species names are given in each panel. The prefix “g” denotes surface molecules, “CH4O” is methanol, and “G-” stands for negatively charged grains.