Shi and co-workers concluded that the use of this method was effective, in that the experimental trends were well reproduced (Figure ). Here, each calculated rate constant is underestimated by at least one order of magnitude, and in many cases the disagreement is by several orders of magnitude. More specifically, the closest agreement observed is for deuterated azulene, where the calculated rate is 1.66% of the experimental rate. They go on to discuss that the quantitative discrepancies between theory and experiment are ultimately due to the limitation of the harmonic approximation, however in the context of virtual screening, the approximation provides a robust means. Martynov and co-workers applied this method in a much more rigorous manner on the polyacenes, calculating Γ ns using 3 separate methods (Pekarian, Hybrid, Gaussian). While the Gaussian function yielded a null rate FIG. . Tabulated calculated and experimental rate constants for the S1 → S0 transition calculated for a series of twelve chromophores. Rates were calculated using Equation . Repurposed from Ref. for numerous transitions, the Hybrid linewidth underestimated the rate. The Pekarian model yielded the most positive results: 1.7×10 -4 s -1 , 1.5×10 3 s -1 , 7.0×10 3 s -1 , and 1.3×10 6 s -1 for naphthalene, anthracene, tetracene, and pentacene S 1 → S 0 transitions, respectively. Some of the higher-order internal conversion pathways were also mapped, but these are difficult to correlate with experiment.