Full-dimensional control of the radiationless decay in pyrazine using the dynamic Stark effect

We present a full quantum-mechanical study of the laser control of the radiationless decay between the B-3u(n pi*) and B-2u(pi pi*) states of pyrazine using the dynamic Stark effect. In contrast to our previous study [Sala et al., J. Chem. Phys. 140, 194309 (2014)], where a four-dimensional model was used, all the 24 degrees of freedom are now included in order to test the robustness of the strategy of control. Using a vibronic coupling Hamiltonian model in a diabatic representation, the multi-layer version of the multi-configuration time-dependent Hartree method is exploited to propagate the corresponding wave packets. We still observe a trapping of the wavepacket on the B-2u(pi pi*) potential energy surface due to the Stark effect for a longer time than the ``non-resonant field-free'' B-2u(pi pi*) lifetime. (C) 2014 AIP Publishing LLC.