Photodetachment band of the fluorenyl anion: a theoretical rationalization

n order to rationalize the experimental photodetachment spectra of the fluorenyl anion, the nuclear dynamics studies are performed using adiabatic and non-adiabatic quantum chemistry ap- proaches. The adiabatic dynamics are performed on the basis of FC Class and Poission simulations. The outcomes from these simulations explain most of the experimental observations. Later, time- independent non-adiabatic nuclear dynamics using vibronic coupling theory (VCT) are performed to elucidate the origin of a few vibrational peaks, which do not appear in the adiabatic dynamics. While the time-dependent non-adiabatic nuclear dynamics using the same VCT are performed to rationalize the lifetime of the excited state of fluorenyl. It is found that the photodetachment band obtained from the non-adiabatic simulations is in better resemblance with the experimental findings.