Calculated NMR lineshapes closely approximate delta functions, so a Gaussian apodiza-tion was applied to the simulated NMR lineshapes to broaden them and better approximate an experimental spectrum. A full-width-half-max (FWHM) of 2 Hz was determined (based on fitting spectra to the starting materials as described herein) and applied to each simulated NMR spectrum. To increase gradient overlap between NMR peaks in the simulated and experimental spectrum, an additional broadening filter was applied to both the experimental and simulated spectra. We found that a Gaussian apodization with FWHM of 10 Hz was sufficient for increasing the gradient overlap in the HMCMC procedure.