Fig. 18. Correlation between experimentally determined ¹³C LLIT DNP scalar dominated enhancements and their calculated AFC (Boltzmann weighted DFT computed Fermi contact hyperfine coupling constant) for the phenylacetylene/TEMPO, benzaldehyde/TEMPO, and nitrobenzene/TEMPO systems. After performing a linear regression with direct weighting of the DNP enhancement error, a line of best fit (y = mx + b) was determined having parameters m = 415 ± 23, b = 21 ± 52, and the goodness of the fit is computed as having an adjusted R² = 0.97.