Modeling the Anharmonic Infrared Emission Spectra of PAHs: Application to the Pyrene Cation

The IR emission cascade from the pyrene cation due to a broad band optical excitation is simulated using kinetic Monte Carlo. Anharmonicities of the ground electronic state potential energy surface are taken into account in the transition energies, the microcanonical densities of states, and the rate of hydrogen loss through various statistical theories. The emission spectral features of the “3.3”, “6.2” and “11.2” μ m bands are computed for different blackbody temperatures.