Fig. 4. (a) (Top) Positions of the substituted deuterium in ImH+-d3, and (bottom) schematics of the model assumed for the spectral simulations. The klib and θlib indicate the frequency of the libration and the libration angle, respectively. (b) Variable-temperature solid-state 2H NMR spectra of 1A (colored solid lines: experimental spectra, black solid lines: simulated spectra). (c) Temperature dependences of the parameters estimated from the spectral simulations: (top) the frequency of libration motion klib; (bottom) libration angle θlib. See also the SI for details.
