Homogeneous stellar structure models for the mass range 8–250 M_⊙ (black symbols). The models are computed for hydrogen mass fractions X_H = 0.7−0 (from bottom to top). Dashed red lines indicate the M − L relations according to Eq. (9) and row No. 1 in Table A.1 for X_H = 0.7, 0.4, and 0.1, and the solid red line corresponds to pure He models according to Eq. (10) and row No. 6 in Table A.1. For comparison, model computations from Ishii et al. (1999) are indicated by red circles. The fitting relations are inferred for the mass ranges of 12–250 M_⊙ (Eq. (9)), and 8–250 M_⊙ (Eq. (10)).