We also report the full-width-half-maxima (FWHM) of our computed lineshapes to compare with the experiment. This value is dependent on our choice of broadening factor. A Gaussian lineshape function with a broadening factor of 600 cm -1 was used to generate the ensemble lineshapes. For both implicit and explicit solvent FTFC spectra, the Gaussian16 default half width half maximum (HWHM) value of 135 cm -1 was used as the FC broadening factor. Although the hybrid E-FC spectroscopy methods include inhomogeneous broadening in the lineshapes, due to the use of a limited number of snapshots to calculate the spectra, the final E-FC lineshapes, especially in zero-temperature spectra, can be noisy. Using 135 cm -1 HWHM results in smoother lineshapes while maintaining the overall lineshape width, see further details in SM, Section S5.