Theoretical ro-vibrational spectrum of CF(+).

Abstract We determined the energies for ro-vibrational transitions of fluoromethylidynium (CF + ) using a numerical variational approach and a Potential Energy Function calculated with the internally contracted multireference configuration interaction method including also the Davidson correction (MRCI+Q). For this purpose, all the CSFs built the full valence space have been selected as multireferential space and all the valence electrons have been correlated for the ground state X 1 ∑ + of CF + . The rotational transitions observed experimentally toward the Orion Bar have been calculated to be 101.2 (102.6) GHz, 202.9 (205.2) GHz and 304.0 (307.7) GHz (experimental values in parentheses) respectively for the J  = 1 → 0, J  = 2 → 1 and J  = 3 → 2 transitions. From the manifold of transitions data, it is shown how to calculate the spectroscopic parameters as well as the coefficients for the Dunham expansion.