Top to bottom: equilibrium values for the resonant angle, eccentricities of the inner and outer planets, and the ratio of the planet’s eccentricity for the models that captured them in a 2:1 MMR. The viscosity models, initial surface density models, and aspect ratio models are depicted from left to right, separated by vertical lines. The square, diamond, cross, and circle markers represent the fiducial model, the overstable models, the non-overstable model captured in the 2:1 MMR, and the limit cycle model, respectively. Additionally, Σ₁ = Σ(r₀).