The independent atom ansatz of density functional theory yields an accurate analytical expression for dynamic correlation energy in the H₂ molecule: Ec = 0.5(1 - √2)(ab|ba) for the atom-additive self-consistent density ρ = |a|² + |b|². Combined with exact atomic self-exchange, it recovers more than 99.5 % of nearly exact SCAN exchange-correlation energy at R > 0.5 A, differing by less than 0.12 eV. The total energy functional correctly dissociates the H-H bond and yields absolute errors of 0.002 A, 0.19 eV, and 13 cm⁻¹ relative to experiment at the tight binding computational cost. The chemical bond formation is attributed to the asymptotic Heitler-London resonance of quasi-orthogonal atomic states ($- (ab|ba)$) with no contributions from kinetic energy or charge accumulation in the bond.
No takes yet. Share an insight, caveat, or question.
Leung et al. (2024) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: