Resonating Hartree-Fock theory of a one dimensional electronic system

The electronic structure of the one dimensional (1D) Hubbard model is calculated by the resonating Hartree-Fock (Res HF) method. As local fluctuations in the spin density wave (SDW) in the half filled case, we consider a solito,-antisoliton pair making quantum trnaslational and breathing motions, i.e., breathers. The breather explains 76.5% (U=3) and 70.1% (U=4) of the ground state correlation energy, which is better than the result of the Gutzwiller method, and gives low energy excited states with the symmetries and energetic ordering characteristic in polyenes