The Model Hamiltonian, Postulated: Hubbard's Two-Term Lattice, Its Own Exact Two-Site Answer, and the Asymptote That Leaves It

Census pricing (row CC-118) of the founding step of Hubbard's 'Electron Correlations in Narrow Energy Bands,' Proc. R. Soc. A 276, 238-257 (1963), against a fixed bench (what is postulated, what is derived, what the postulates return numerically, what they cannot reach). The step is one truncated Hamiltonian: the solid's Coulomb problem replaced by postulation with two terms (nearest-neighbour hopping t, on-site repulsion U), every longer-range interaction, further band, and lattice dynamics deleted, with U and t free parameters. Verified in the notebook (7 checks, exit 0) from the postulated Hamiltonian alone on the two-site, two-electron bench with t declared as the unit: ground energy from -2.000000t at U = 0 to -0.039984t at U/t = 100, ionic (double-occupancy) weight from exactly 0.500000 to 0.000400. Remainders at full size: the field's own asymptote J = 4t^2/U departs from the model's own exact gap by 10% at U/t = 6.0302, by 20.71% at U/t = 4, and by 156.16% at U/t = 1; neither parameter is set for any material in the founding text; and the deleted terms have no states in the model's Hilbert space, so the truncation's error is not a number the model can print about itself. Scout-grade verification disclosed on the manuscript's face (CC-91 form): no verbatim quotation, no page-specific claim. EXTENSION. Vacuum catastrophe NOT SOLVED; quantum gravity NOT SOLVED.