REPULSIVE WALL OF THE HE-2 INTERACTION AS INFERRED FROM DIFFERENTIAL CROSS-SECTIONS

The repulsive wall of the ground-state He-2 interaction potential betw een 0.5 and 2 angstrom is determined by optimizing model potentials in order to fit the combined differential-cross-section data of Newman e t al. [J. Geophys. Res. 90, 11 045 (1985)] and Nitz et al. [Phys. Rev. A 35, 4541 (1987)]. The results for two distinct forms of the model a re consistent with one another and yield a potential which agrees with the semiempirical Hartree-Fock dispersion [HFD-B(He)] potential of Az iz et al. [Mol. Phys. 61, 1487 (1987)] near 1.6 angstrom but rises les s steeply with decreasing internuclear separation.