Parameter dependences of Lifson–Roig-modeled fractional helicities FH for Ala22 and Ala12 peptides. The temperature dependence of FH values is modeled by varying the length-independent values for w. Magenta lines are calculated for Ala22, orange lines for Ala12. Continuous lines correspond to FH for strong cap stabilization: j = 200, c = 7; broken lines correspond to weak cap destabilization: j = c = 0.5. Symbols drawn as squares (Ala22) and circles (Ala12) report FH calculated from the wAla(n,T) of Figure 2: red: T = 60 °C, green: T = 25 °C, blue: T = 2 °C. Filled symbols correspond to j = 200, c = 7; open symbols correspond to j = c = 0.5. Symbols have been positioned on appropriate line sites at which FH values are equal; thus, an average w (and temperature) is assigned to the wAla(n,T)-derived FH. These sites thus define approximate fixed-w assignments for the four peptides.