Fig. 1.

The molecular structure of TB6 and pulse sequence configuration. (Top Left) The molecular structure of TB6. The Purple sections are the helices, the yellow sections are the β-strands, and the green and white sections are randomly coiling structures. (Top Right Upper) Pulse configuration for heterodyne four-wave mixing techniques. k₁, k₂, and k₃ are the input pulses, and k_s is the signal generated, which is in the same direction as the detection pulse k₄.(Top Right Lower) The pulse sequence for coherent 2D experiments. t_i are the time intervals between the pulses, and τ_i is the peak time of pulse i. (Middle) Red, linear absorption; black, AS(α); green, AS(β); blue, AS(γ); purple dash, the difference of the additive and the actual spectrum. (Bottom) Motif content of the vibrational eigenstates of TB6. Red, α; green, β; blue, random coil. The plot is vs. mode number; the (nonuniform) frequency scale is given at the top.