The impact of the CO chemical transition at the core on the distribution of period spacings and kinetic energies of oscillation of the new models. Left panel: ℓ = 1 forward period spacing ΔΠ in terms of the pulsation periods, for a decreasing magnitude of Ledoux term B at the CO chemical interface (B_OC), from the top to the bottom panel. The curves have been artificially displaced up for clarity, where y-axis values make sense only for the case B_OC = 0. Right panel: similar to the left panel, but for the oscillation kinetic energy. The models have T_eff ∼ 12 000 K, M_⋆ = 0.5932 M_⊙, and thick H envelopes.