Example of degeneracy: three different stellar structure models with similar period spacing patterns. All three models have the same values for the metallicity Z, X_s and mode classification. They were constructed by setting the values of M_μ and H_slope and allowing the values of mass M, X_c, Ω/Ω_crit and curvature α to vary. The red, blue and green models correspond to M_μ = 0.25, 0.25, and 0.28 and H_slope = 3.8, 3.8, and 4.2, respectively. These changes are reflected in the left panel. Left panel: Hydrogen abundance profile as a function of mass coordinate for each model. Middle panel: Brunt-Väisälä profile as a function of normalised buoyancy radius. Right panel: Period spacing patterns.