Quantum Dynamics Study of Photoexcited Aniline

A model Hamiltonian based on the quadratic vibronic coupling model is developed to describe the photoinduced dynamics of aniline excited to the manifold of states comprising its first six singlet electronic states. The model Hamiltonian is parametrized by fitting to the results of extensive EOM-CCSD calculations and its validity tested through the calculation of the first two bands in the electronic absorption spectrum of aniline. It is found that two previously neglected 3p Rydberg states play an important role in the dynamics of aniline following excitation into the first two (1)pi pi* states. Assignments of the vibrational structure seen in the experimental spectrum is made, and the role played by the Herzberg-Teller effect in excitation to the first (1)pi pi* state is analyzed.