Certificate data for "A Bound Helium Dianion Does Not Exist"

Certificate data for the paper “A Bound Helium Dianion Does Not Exist” (A. Shelley, D. M. Tartakovsky, 2026), a computer-assisted proof that the nonrelativistic four-electron helium Hamiltonian has no eigenvalue below the three-electron ground-state energy, so a helium nucleus binds at most three electrons. The proof reduces the theorem to the pointwise nonnegativity of an explicit function of three variables on a bounded region; this record contains the interval-arithmetic certificate of that inequality (50.4 million boxes with rigorous lower bounds, no failed box), the coefficient file defining the function, the evaluators, drivers and logs exactly as run, the coverage audit, and a script to re-check any box. README.md explains the layout and the file format. The main file is he2minus_certificate_v1.tar.gz (570 MB; sha256 in the accompanying .sha256 file). The development code is archived separately as a software record (10.5281/zenodo.23754394). Data CC BY 4.0; code in this record MIT (LICENSE-CODE).