Key points are not available for this paper at this time.
We obtain the exact solution of a general Hubbard chain with kinetic energy t, bond-charge interaction X, and on-site repulsion U with the only restriction t=X. At zero temperature and half filling, the model exhibits a Mott transition at U=4t. In the metallic phase and near half filling, superconducting states are part of the degenerate ground state and are favored for small U if the system is slightly perturbed.
Arrachea et al. (Mon,) studied this question.