Relationship between g₁ and the slope of the post-collision mass function, α_pc (for stars in the mass range 0.2–0.8 M_⊙), for various shapes of the IMF, namely for various values of the slope in the intermediate-mass range, α₁, and for various values of f_ext. In all models, the values of α₀ and α₂ are fixed to −0.3 and −2.3, respectively. The models are compared to the (N(G1)/N(tot)) − α_pd found in the observations.