The sigmoid width parameter of the native contacts curves, full-width half maximum of the heat capacity curve, and the melting point computed from both the heat capacity and native contacts curves, are also plotted. For each of the angle force constants considered, torsion force constants of 0.667 and lower do not sufficiently stabilize the helical backbone, leading to broad heat capacity curves and ill-defined native contacts (omitted from the native contact fraction plots). Due to the slower kinetics of folding for low torsion force constant, replica exchange simulations for k t = 1.333 and lower were run for 400 ns instead of 200 ns, with the last 100 ns used as the production period. Of the torsion force constants tested, values of 1.333-2.000 lead to the most cooperative transition, characterized by the smallest sigmoid width and heat capacity full-width half-maximum parameters. Upon increasing the torsion force constant from 2.0, the sigmoid width increases and the melting point increases, highlighting the tradeoff between high cooperativity and high stability. These trends in characteristic width and melting point hold true for all values of k a considered.