Normalized second-order growth functions (solid curves) and (dashed curves) for a symmetron model with a_ssb = 0.33, m₀ = 1 h Mpc⁻¹ and β = 1 at redshift z = 0. We consider equilateral (brown) and orthogonal (red) triangle configurations. The bottom panel shows their ratio. Regions with values greater than 1 correspond to wave numbers for which the growth is enhanced by the screening contributions.