Interatomic potentials for the Na+—Rg complexes (Rg = He, Ne and Ar)

Interatomic potential energy curves are presented for the Na+—Rg (Rg = He, Ne and Ar) cationic complexes. The curves are calculated at the CCSD(T)/aug-cc-pVQZ level of theory, with correction for basis set superposition error being performed point-by-point. Ninety-six different bond lengths are used in the generation of the curves. From the curves rovibrational energy levels are calculated. These, in turn, are used to calculate the heat of formation of the cationic complexes, both by calculating partition functions under the assumption of a rigid rotor, harmonic oscillator, and also explicitly using the calculated rovibrational energy levels. The long range region of each of the curves is used to derive the D 4 and D 6 parameters, the former being used to derive the static polarizability a 1 of each of the Rg atoms and the latter the first dispersion coefficients, C 6(Na+—Rg).