As we have seen in Eq. ( ), a molecule with a 3 NEA does not alter this picture for BA. The histogram for the direct SOC is a near Gaussian distribution around a mean close to the vertical value. The distribution has a secondary peak near zero dipoles, revealing that points with a 3 * T1 minimum were also sampled in the nuclear ensemble. The indirect mechanisms are near exponential distributions, with the mean also near the vertical values. Between the two indirect mechanisms, the SOC-dipole is about twice more intense as the dipole-SOC for both vertical and NEA (see Table ). MeBA, having a 3 n* T1 minimum like BA, shows the same scenario, as we can also observe in Figure and Table . Nevertheless, the contributions to the singlet-triplet transition dipole are completely distinct when considering MoBA and DMABA. Both molecules have 3 * T1 minima; direct SOC should not contribute, as we can see in Eq. . The vertical contributions are nearly null for all three terms in Figure , explaining the 272 ms and 114 ms long lifetimes of MoBA and DMBA, respectively. Note, however, that when vibronic couplings are introduced via NEA, the contributions from the three mechanisms increase significantly. As a result, the NEA phosphorescence lifetime drops to 2.67 ms in MoBA and 4.12 ms in DMABA, revealing a remarkable vibronic effect. As we can see in Table , direct and indirect couplings contribute equally to the transition dipole moment in MoBA and DMABA.