Miyazaki & Ananth used a singularity-free casting to calculate the rate constants for the smaller polyacenes and azulene, and find rates of 2.7 × 10 9 s -1 , 1.1 × 10 7 s -1 , 4.2 × calculate the rates of a number of pyrazine derivatives, and find rates of 4.45 × 10 9 s -1 and 3.29 × 10 5 s -1 at room temperature for 2,3dicyano-5,6-diphenylpyrazin and 2,3-dicyanopyrazino phenanthrene, respectively. Importantly, they probe Duschinsky effects in both systems, and find them to be vital in the description of the former, and much less to in the latter. Interestingly, they also probe temperature effects, with (again) the former being more sensitive to temperature effects (an order of magnitude shift between 20 K to 300 K). Humeniuk and co-workers found that the broadening function used can drastically effect the rate of internal conversion, with this dependence weakening at the rates become large. A Voigt profile was found to yield significantly large rate constants when compared to those calculated using a Gaussian profile (Table ), whereby a strong relationship can be observed between the rate constant and the width of the Lorentzian, as opposed to the structure of the vibrational continuum itself, with this effect becoming more pronounced for those systems in which Duschinsky rotations were more important. Adjacently, Wenzel & Mitric calculate internal conversion for a series of molecular compounds within the extended thawed Gaussian approximation as well as the vertical and adiabatic harmonic models, and found rate constants would vary drastically depending on the choice of density functional and the Gaussian lineshape function (Table ). Unlike those results reported by Humeniuk and co-workers , variability in rate constants was within an order of magnitude. Rybczński and co-workers[163] examined a series of benzothiazole-difluoroborate substituted derivatives, and found rate constants between 0.26 -7.87 × 10 8 s -1 , depending on the specific substitution. They also noted a strong dependence on this method to the broadening function employed, with order of magnitude shifts for 4 of the 9 systems examined.