Some remarks on the stability of the ground and excited electronic states of the CF2++ dication

The dissociation path of the ground state of CF2++(1Σg+) is investigated by means of the multi-reference averaged quadratic coupled cluster (AQCC) method using an ANO type basis set. Low lying electronically excited states involved in the dissociation are also calculated. The CF2++(1Σg+) dication has to be considered as metastable (ΔEDiss=−8.5 kcal/mol). However, the dissociation into the ground states of the products (i.e., CF+(1Σ+) and F+(3P)) is spin forbidden. Further, the surface crossing of the ground-state potential energy surfaces (PES) with the lowest triplet surface (3A′) occurs around the C–F distance of 1.85 Å. The related barrier is calculated to be ∼5 eV.