Jahn-Teller and pseudo-Jahn-Teller effects in trifluoromethane radical cation

•The Jahn-Teller and pseudo-Jahn-Teller effects in trifluoromethane are investigated here.•Extensive ab initio computation of PESs are performed.•Full quantum dynamics are obtained by both time-independent ant time-dependent manner.•The internal conversion rate for the A˜ and B˜ states are ∼64 fs and ∼18 fs.•My results compare well with the experimental data.

Jahn-Teller (JT) and pseudo-Jahn-Teller (PJT) effects in the ground, first and second excited electronic states of the trifluoromethane radical cation are theoretically examined here. Extensive ab initio computation of electronic potential energy surfaces and their coupling surfaces are performed. Full quantum dynamics are obtained by both time-independent and time-dependent quantum mechanical methods. This system belongs to (E+A)⊗e   JT-PJT family. Our results compare well with the experimental data. JT interactions are fairly strong in the second excited B˜2E electronic state and the PJT interaction between A˜2A2 - B˜2E electronic states is stronger which cause an increase of the spectral line density of the vibronic spectrum.