As explained in Section II.2, the NEA simulations require an ensemble of nuclear geometries representing the distribution of configurations in the source state. When simulating absorption spectra, sampling a Wigner distribution is convenient for building such an ensemble. However, for fluorescence simulations, the Wigner sampling would only be adequate for a regime in which the entire photon energy excess was dissipated into the environment, leaving the molecule at its zero-point energy level. This intense dissipation is not expected to occur in pyrene in a collisionless regime. Therefore, dynamics simulations are more adequate for building the ensemble in this case.