Hartree-Fock Bound States for Molecule-Ions HeC" and Hec

Interaction potentials, spectroscopy and transport properties of C+(2PJ) and C+(4PJ) with helium

“…The present spectroscopic results could prove useful for trying to detect the C + -He complex in the interstellar medium, as suggested by Harrison et al 7 although whether sufficient quantities would be present is not clear, with direct formation of the complex requiring three-body stabilization by another atom/molecule or surface; also, ligand exchange is also unlikely owing to the low binding energy. We note the importance of accounting for ion mobilities in determining accurate rate coefficients, 24 particularly for slow reactions; the present calculated mobilities at a range of temperatures will clearly be useful in such investigations.…”

“…6 Chemistry mostly starts with interactions between species, and the interactions of atomic cations with rare gas atoms are generally agreed to be amongst the simplest interactions that can be probed, especially when the rare gas is the very non-polarizable helium atom. Indeed, the C + -He complex has been proposed as a possible species in the interstellar medium by Harrison et al 7 and interactions between C + and He could be a cooling mechanism for C + ions in the interstellar medium and dense interstellar clouds. 8 Interatomic potentials are also important in the calculation of a range of quantities including collision cross sections -important in the calculation of ion transport data -and atomic collisional energy transfer.…”

On bonding in transition-metal helide ions

“…On the theoretical side, ab initio calculations on Belle 2+ [4][5][6], CHe 2+ [7] and HeCN + [8 (a)] indicate rather strong bonding, a D e of about 0.65-0.8, 0.4 and 1.5-2 eV, respectively. Cooper and Wilson [8 (b)] reported HartreeFock level studies on AHe 2+ A = C, N, O, on CHe n+, n = 1-7 and on further polyatomic helides.…”

Noble gas molecular ions

“…Calculated potentials for the first 4Z-and 2Z+ states of NHe z+ were found to have higher energies than the ~II state. The ion CHe 2÷ has been previously studied by Harrison et al [18] who found a dissociation energy of c. 3000 cm -1 and a bond length of 1.72 A (c. 3"3 a0).…”

“…The CHe + ion has been previously studied by Harrison et al [18] using a basis set consisting of Gaussian-type orbitals. For the 21-I state they predicted a dissociation energy greater than c. 200 cm -I and a bond length of 2.59 A (c. 4.9 a0).…”