Within the framework of the Frank-Condon principle, calculation of the overlap between different vibrational modes in the ground and excited state allows calculation of the vibrationally coupled emission spectra. This framework has now been expanded to calculate spin-forbidden phosphorescent emission, and has been used to study emission from a growing number of phosphorescent platinum, iridium and gold complexes. There is good agreement between the simulated and experimental PL spectra (Figure ). The highest energy (0-0) peak in the emission spectrum does not correspond to the most intense peak, highlighting the significant contribution of vibrational modes to the shape of the PL spectra in these complexes. a Emission wavelengths are calculated as a vertical transition from the optimized T1 structure.