Here, clear distinctions (with non-overlapping standard deviations) can be found between the two structural motifs in the coupling constants. For instance, the coupling between the two classical amide III vibrations (localized modes 3 and 4) is rather small for the β-strand region, and significantly larger for the α-helix region. Conversely, the coupling between localized mode 1 (C α -H bending) and localized mode 3 (classical amide III) is substantially larger for the β-strand region compared to the α-helix region.