Rovibronic energy levels of HeHF + (X 2Π)

Abstract

Ab initio coupled electron pair (CEPA) potential energy functions have been used to calculate the energies of low-lying rovibronic ( J ⩽ 5 2 ) levels in the X 2Π state of HeHF + (for R HF + = 1.892 bohr). The complex was found to have a linear equilibrium structure, the dissociation energy D e has been calculated to be 1490 cm −1, and the equilibrium R He…HF + distance (relative to the center of mass of HF +) to be 4.25 bohr. The pattern of the rovibronic levels can be best characterized by a notation used for linear/linear Renner—Teller states. The stretch wavenumber (Π 3 2 (0,0)-Π 3 2 (1,0)) has been calculated to be 311.0 cm −1, the bend wavenumber of (Π 3 2 (0,0)-Σ + 1 2 (0,1)) to be 223.2 cm −1, and the spin—orbit splitting (Π 1 2 (0,0)-Π 3 2 (0,0)) to be 319.6 cm −1.