The Jahn-Teller effect in the ground electronic state of the tetrafluoromethane cation before dissociation: a promoter of the anisotropic fragmentation

The role of multimode Jahn-Teller coupling effect on the anisotropic fragmentation of in its electronic state is investigated theoretically via an ab initio quantum dynamics study. The potential energy surfaces up to two-dimensions of nuclear coordinates are established from extensive electronic structure calculations. A higher order (seventh-order) diabatic vibronic coupling model Hamiltonian is necessary to mimic the ab initio potentials and thereby constructed. The theoretical results are in good agreement with experimental observations. A detail analysis of the relevant static aspects and the vibrational progressions under the structureless and broad vibronic band of are made. Present study suggests that the Jahn-Teller effect is operative before the dissociation of upon photoionisation and responsible for the experimentally measured anisotropic fragmentation in the electronic state of the title cation.