We recognized that the C--O and ψ-angle distributions obtained from Raman measurements provide structural constraints that can be used to determine molecular structural models of the amylin 20-29 and Aβ 25-35 fibril polymorphs. To accomplish this, we first manually constructed putative structures of the three different fibril polymorphs for MD simulations (see Computational Methods for details). Then, using an analogous approach to ssNMR, we performed an energy minimization procedure using MD wherein we restrained the C--O and ψ-angles using the equilibrium angles and torsional force constants determined experimentally from Raman measurements (vide supra).