Probing of these hypotheses was conducted through a study in the exciton dynamics of perylene diimide and tetracene hetero-and homo-geneous substrates , whereby the rate constants for both chromophores were found to stabilise significantly through the use of a dispersion correction. However, in a follow up work, Manian and co-workers found that the issue may also be due to how different density functionals treat the electronic-nuclear coupling between two electronic excited states, where they tested the ShaMan method on base perylene using 15 different density functionals across two different triple-ζ basis sets. Here, they found that while for internal conversion, rate constants across each density functional/basis set combination would vary, in some cases by several orders of magnitude (Table ). Interestingly, this serves as an additional reason as to the disagreement previously observed but not discussed by Valiev and co-workers . found a similar pattern of behaviour in their calculated rate constants, concluding that the calculated vibronic coupling matrix elements nonadiabatic coupling elements were subject to this affect, among other factors. Further probing found the secondorder corrected rate constant to heavily depend on the method used to obtain the electronic Hessian. From these results, 5 density functional/basis set combinations were found to yield an appreciable rate constant for the S 1 → S 0 transition when compared directly to experimental results. Interestingly, Veys and co-workers noted a similar disagreement with respect to the choice of density functional, however their calculations highlighted a relatively consistent disagreement whereas Manian and co-workers highlighted multiple orders of magnitude differences.