  We obtain the exact solution of a general Hubbard chain with kinetic energy
$t$, bond-charge interaction $X$ and on-site interaction $U$ 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.
