Details of the different enhancements on the abundance of ²²Ne (solid lines) and the corresponding abundances of ¹²C (long-dashed lines) and ¹⁶O (short-dashed lines) in the models reported in Table 1. Case A or “half” (left panel): half of all ²²Ne concentrated in a central ball with the azeotropic composition and the other half uniformly distributed through the rest of the WD. Case B or “full” (central panel): all ²²Ne concentrated in a central ball with the azeotropic composition. Case C or “shell” (right panel): oxygen-rich inner region with X(²²Ne) = Z, followed by a narrow shell rich in ²²Ne and depleted of oxygen, and then a CO envelope with no ²²Ne.