ROVIBRONIC ENERGY-LEVELS OF HEHF+ (X(2)PI)

Ab initio coupled electron pair (CEPA) potential energy functions have been used to calculate the energies of low-lying rovibronic (J less-than-or-equal-to 5/2) levels in the X 2PI 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 4.2 5 bohr. The pattern of the rovibronic levels can be best characterized by a notation used for linear/linear Renner-Teller states. The stretch wavenumber (PI3/2 (0,0)-PI3/2(1,0)) has been calculated to be 31 1.0 cm-1, the bend wavenumber (PI3/2(0,0)-SIGMA1/2+(0,1)) to be 223.2 cm-1, and the spin-orbit splitting (PI1/2(0,0)-PI3/2(0,0)) to be 319.6 cm-1.