Ternary phase diagram of the TDR model. The projections of each point on the medians of the equilateral triangle show the contributions of each phase (ambient medium, active dissipative bursts, and relaxation stages) to the total column density of a given species. In the left panels, the models are computed for several values of A_V: 0.1, 0.2, 0.3, 0.4, 0.6, 0.8, and 1.0 mag. In the right panels, the models are computed for several values of n_H: 20, 30, 50, 100, and 300 cm^-3. All the other parameters are set to their standard values (see Table 1). In all panels, the size of the symbols increases as the varying parameter increases. The beige, yellow, and orange zones indicate the regions where the production of the different species is dominated by the ambient medium, the active vortices, and the relaxation stages, respectively.