Effect of hubbard interaction on solitonic excitations in polyacetylene

We have studied the effect of Hubbard interaction on solitonic excitations in the polymer trans ‐polyacetylene. These excitations are modeled using the Su, Schrieffer, and Heeger (SSH) Hamiltonian. Within this framework, we have calculated the full configuration interaction and restricted Hartree‐Fock energies of solitonic excitations in trans ‐polyacetylene chains with 4–10 carbon atoms. These results are extrapolated to longer chains, and it is shown that the correlation energy for these chains approaches 3%. Thus, our calculations provide a justification, hitherto absent, of the accuracy of the Hartree‐Fock calculations reported in the literature.