Reference Label	Details
Huber 1979	K. P. Huber and G. Herzberg, "Molecular Spectra and Molecular Structure. IV. Constants of Diatomic Molecules", Van Nostrand Reinhold: New York 1979
est unc	estimated uncertainty
Olson 1967	R. E. Olson and C. R. Mueller, J. Chem. Phys. 46, 3810-3817 (1967) Inversion of Low-Energy Experimental He - He+ Elastic Differential Scattering Sections to the 2Sigmag+ and 2Sigmau+ Potentials