Fig. 10.

A typical example of the R_1ρ relaxation decay with barely noticeable multi-exponentiality, measured on GB1 at 21.5 °C, 20 kHz MAS and a spin-lock field of 17 kHz. The dashed blue and solid red lines are single- and bi-exponential fits, respectively. The relaxation rates obtained from the single- and bi-exponential fits are 6.5 ± 0.25 and 8.0 ± 1.0 s⁻¹, respectively. In the latter case, the mean relaxation rate (i.e. initial slope) was obtained as $〈R_{1\mathit{\rho }}〉=p·R_{1\mathit{\rho }a}+(1-p)·R_{1\mathit{\rho }b}$, where p and R_1ρa,b are the relative amplitude of one of the components and relaxation rate constants of two components of the decay, respectively (see Eqs. S1–S4 of ESM). The fitting values of these parameters are: p = 0.74 ± 0.5; R_1ρa=2.8 ± 5 s⁻¹; R_1ρb=23 ± 20 s⁻¹