Mobility of O+ in He and interaction potential of HeO+

Interaction potential and transport properties of NeO+

The results of both experimental and theoretical studies of the mobility of O(+) in Ne are reported. Errors in the experiments have been carefully assessed, allowing the obtained data to serve as stringent tests of the ab initio potentials. These potentials were calculated using the RCCSD(T) method, employing basis sets of quintuple-zeta quality. Curves were calculated for the lowest (4)Sigma(-) state [arising from O(+)((4)S) interacting with Ne] and for the (2)Pi state [arising from O(+)((2)D) interacting with Ne]. Then, the effects of spin-orbit coupling were incorporated by using the Breit-Pauli operator. The resulting ground state (Omega=32) of NeO(+) gives mobility values in good agreement with experiment at all field strengths. Values of spectroscopic quantities for the ground electronic state of NeO(+) are also presented.

Accurate potential energy curves for F−–Rg (Rg = He–Rn): Spectroscopy and transport coefficients

High-quality ab initio potential energy curves are presented for the F(-)-Rg series (Rg = He-Rn). Calculations are performed at the CCSD(T) level of theory, employing d-aug-cc-pV5Z quality basis sets, with "small core" relativistic effective core potentials being used for Kr-Rn. The quality of the curves is judged by agreement with recent high-level calculations in the case of F(-)-He and F(-)-Ne and by excellent agreement with mobility data for the systems F(-)-Rg (Rg = He-Xe). Except for these recent high-level calculations on the two lightest systems, we are able to deduce that all other previous potentials for the whole set of these systems are inadequate. We also present spectroscopic information for the titular species, derived from our potential energy curves.